Error messages—. These messages indicate that DOS has encountered a problem with a command or with the syntax you used. Execution stops when DOS displays an error message.

Warning messages—. These messages tell you that the next action you take might cause unwanted changes to files or to your system; they often include a prompt, which enables you to select an action.

Information messages—. These messages display needed information about your system's operation or your DOS version's performance. Like warning messages, these messages also often include a prompt.

Warning: CHKDSK found noncontiguous blocks on drive d. If you like, you can use a defragmenter to eliminate the fragmentation or use COPY or XCOPY to transfer the fragmented files to a freshly formatted floppy disk in a sequential form.

Error: You have attempted to use LOADHIGH (or LH) with the /L parameter referring to a nonexistent UMB area. The best way to correct this problem is to rerun MemMaker.

Error: You have installed a terminate-and-stay resident program (TSR) that leaves insufficient memory for BACKUP. Examples are PRINT or some forms of MODE. The resident program must be unloaded before you can continue the backup. Use MEM /C to see which TSR was loaded last.

Error: You or a program attempted to change or erase a file that is in use or marked as read-only. You can change the read-only attribute by using the ATTRIB command.

Information: You issued CHCP, which displayed the code page currently in use by the system (represented by xxx).

Information: You issued MODE, which lists the code page (xxx) currently in use for the device (ddd). To display a single screen at a time, pipe this command into MORE (MODE|MORE).

Error: You used KEYB with a code page not supported on the CON device (screen).

Prompt: You issued REPLACE /P. DOS asks whether you want to add the file to the disk.

Information: REPLACE displays this message while adding filename to your disk.

Error: No room remains for logical drives in the extended partition. Use FDISK to change the size of the extended partition.

Information: You issued PRINT /T, which removes all files from the print queue.

Warning: You issued DEL or ERASE with the *.* wildcard. To continue, press Y; to cancel, press N. Then press the Enter key.

Information: While using FDISK, you removed all logical drives associated with the extended DOS partition.

Information: None of the files you specified (to CHKDSK) are fragmented.

Warning: The contents of a file have been truncated because the size indicated in the directory is inconsistent with the amount of data allocated to the file. Use SCANDISK or CHKDSK /F to correct the discrepancy.

Error: The version of DOSKey you are trying to run is incompatible with the one in memory. Make sure you don't mix the DOSKEY.COM that comes with DOS 6.0 with the version that comes with DOS 6.2 or another vendor's command-line editor.

Warning: While using MODE, you requested a screen function that cannot be performed until you load ANSI.SYS.

Information: You tried to issue APPEND with /X or /E after previously using APPEND. You can use the /E switch only the first time you type APPEND after starting your system. You can use the /X switch only if it was used during initialization.

Warning: You cannot use APPEND on an assigned drive. Cancel the drive assignment before using APPEND with this drive.

Error: SMARTDRV has detected a hard disk error when write caching was enabled. Because the application might have already continued with something else, the usual corrections don't apply. Write caching must be enabled for only reliable media.

Error: You tried to print the background color by using GRAPHICS /B, but you do not have a color printer connected to your computer.

Information: This message appears while you back up files to the specified drive.

Error: You entered an invalid name for invoking a command, program, or batch file. The most frequent causes are misspelling a name, omitting a required disk drive or pathname, or omitting the command name when giving parameters (for example, omitting the WordStar command, WS, by typing MYFILE instead of WS MYFILE).

Check the spelling on the command line and make sure that the command, program, or batch file is in the location specified. Then, try the command again.

Error (startup): DOS does not start because it cannot find COMMAND.COM, the command interpreter.

If this message appears during startup, COMMAND.COM is not on the startup disk or a COMMAND.COM file from a previous version of DOS is on the disk. If you used the SHELL command in CONFIG.SYS, the message means that the SHELL command is improperly phrased or that COMMAND.COM is not in the location you specified.

With DOS 6.0 or 6.2, you can override CONFIG.SYS by using the F8 or F5 key while booting. This solution works if the correct COMMAND.COM is in the root directory. Otherwise, place another disk that contains the operating system (IO.SYS, MSDOS.SYS, and COMMAND.COM) in the floppy disk drive and reset the system. After DOS starts, copy COMMAND.COM to the original startup disk so that you can boot DOS in the future.

Error: If this message appears while you are running DOS, there are several possibilities: COMMAND.COM has been erased from the disk and directory you used when starting DOS, a version of COMMAND.COM from a previous version of DOS has overwritten the good version, or the COMSPEC entry in the environment has been changed. You must restart DOS by resetting the system.

If resetting the system does not solve your problem, restart the computer from a copy of your DOS master disk. Copy COMMAND.COM from this disk to the offending disk.

Warning (startup): The device driver filename was not found, an error occurred when the device driver was loaded, a break address for the device driver was beyond the RAM available to the computer, or DOS detected an error while loading the driver into memory. DOS continues booting without the device driver filename.

If DOS loads, check your CONFIG.SYS file for the line DEVICE=filename. Make sure that the line is typed correctly and that the device driver is at the specified location; then reboot the system. If the message reappears, copy the file from its original disk to the boot disk and try starting DOS again. If the error persists, the device driver is bad; contact the dealer or publisher who sold you the driver.

Warning: DOS cannot find KEYBOARD.SYS as specified by the KEYB command. Solving this problem might take several steps. First, check to make sure that KEYBOARD.SYS exists and is in the correct path; then retype the KEYB command. If you get the same message, KEYB.COM or KEYBOARD.SYS might be corrupted.

Error: While using FORMAT, DOS was unable to find a DOS partition on the fixed disk you specified. Run FDISK and create a DOS partition on this fixed-disk drive.

Error: DOS could not find the batch file it was processing. The batch file might have been erased or renamed. With DOS 3.0 only, the disk containing the batch file might have been changed, causing DOS to abort processing of the batch file.

If you are using DOS 3.0 and you changed the disk that contains the batch file, restart the batch file without changing the disk. You might need to edit the batch file so that you do not need to change disks. This procedure applies only to DOS 3.0.

If the batch file includes a RENAME command that causes the originating batch filename to change, edit the batch file to prevent renaming when the batch file is processed again. If the file was erased, re-create the batch file from its backup file if possible. Edit the file to ensure that the batch file does not erase itself.

Error: When using MODE COMx commands to set any COM port parameters, you must at least indicate the baud rate.

Information: When you use BREAK by itself, one of these messages displays the current BREAK setting. You can set BREAK at the command line or in CONFIG.SYS.

Error: When DOSKey has been loaded into memory, you cannot change the buffer size.

Error: CHKDSK was unable to go to the specified directory. No subdirectories below this directory are verified. Run SCANDISK or CHKDSK /F to correct this error.

Error: CHKDSK was checking the tree structure of the directory and was unable to return to the root directory. Remaining subdirectories were not checked. Restart DOS. If the message continues to appear, the disk is unusable and must be refor matted.

Warning: You cannot use CHKDSK to check drives redirected over the network.

Warning: You cannot use CHKDSK to check substituted or assigned drives.

Error: While using FDISK, you tried to create a partition of 0% (0 megabytes). To correct this error, you must allocate 1% (or a minimum of 1MB) of hard disk space to any partition you create.

Error: While using FDISK, you tried to create an extended DOS partition before giving your first fixed-disk drive a primary DOS partition. To correct this problem, simply create a DOS partition on your first fixed-disk drive. When this operation is complete, you can create an extended DOS partition if you have room on this disk or if you have a second fixed disk.

Error: When using FDISK, you must create an extended DOS partition before you can create a logical drive.

Error: You cannot compare disks on any disk drive that has been reassigned to a network.

Error: When using FDISK to delete an extended DOS partition, you first must remove any logical drives.

Error: You attempted to copy a floppy disk to a drive that was redirected to a computer network. DISKCOPY does not copy disks directly to a networked disk drive. Use COPY to copy the disk.

Error: You tried to copy from a device by using the /B switch. To complete the copy process, use the ASCII (/A) switch to create an ASCII copy. You also can use the COPY command without the /B switch.

Error: EDIT.COM or HELP.COM cannot find the QBASIC.EXE program file. QBASIC must be available to edit a file or access the MS-DOS online help system.

Error: You did not give the path of the GRAPHICS.PRO file; DOS could not find it in the current directory.

Error: While running FORMAT, you specified a drive that did not have the system files in the root directory.

Error: You tried to format a disk in a drive being used by a network.

Error: You attempted to format a drive that was mapped to another drive with ASSIGN or SUBST. To perform a successful format, you must run ASSIGN or SUBST again to clear the drive assignments.

Error: You attempted to label a drive created with JOIN, SUBST, or ASSIGN.

Error: You cannot use LABEL with drives redirected over the network.

Error: DOS attempted to reload COMMAND.COM, but the area where DOS keeps track of memory was destroyed or the command processor was not found in the directory specified by the COMSPEC= entry. The system halts.

This message might indicate that COMMAND.COM was erased from the disk and directory you used when starting DOS, or that the COMSPEC= entry in the environment has been changed. Restart DOS from your usual startup disk. If DOS does not start, the copy of COMMAND.COM has been erased. Restart DOS from the DOS startup or master disk and copy COMMAND.COM to your usual startup disk.

Alternatively, an errant program might have corrupted the memory allocation table where DOS tracks available memory. Try running the same program that was in the computer when the system halted. If the problem occurs again, the program is defective. Contact the dealer or publisher who sold you the program.

Warning: The LOADHIGH (or LH) command is used only for TSR programs. Batch files might not be run this way.

Error: When using MOVE with wildcards for the source file specification, you must specify a directory for the destination. The most common cause of this error is a misspelled name.

Error: When using XCOPY /S, you cannot specify a target that is a subdirectory of the source. You might use a temporary disk or file to bypass this limitation if the directory tree structure allows a temporary disk or file.

Error, Warning: The .. entry (the parent directory) is defective and cannot be recovered. If you have specified the /F switch, CHKDSK tries to correct the error.

Error: FASTOPEN cannot correctly access expanded memory (EMS).

Error: You specified the default drive as a SYS destination. Switch to another drive before issuing the SYS command.

Error: You or one of your programs directed DOS to load another copy of COMMAND.COM, but DOS could not load it. Your CONFIG.SYS FILES command is set too low, or you do not have enough free memory for another copy of COMMAND.COM.

If your system has 256KB or more and FILES is less than 10, edit the CONFIG.SYS file on your startup disk, using FILES=15 or FILES=20. Then., restart DOS.

If the problem recurs, you do not have enough memory in your computer, or you have too many resident or background programs competing for memory space. Restart DOS, loading only the essential programs. If necessary, eliminate unneeded device drivers or RAM disk software. You also can obtain additional RAM for your system.

Error: You cannot substitute drives redirected over the network.

Error: You cannot transfer system files to drives redirected over the network.

Error: You attempted to use FASTOPEN over a network, with a floppy disk drive, or with more than four disks at one time.

Error: You tried to use PRINT over the network. Use NET PRINT or consult your system administrator for the correct procedure for printing files over the network.

Error: The specified XCOPY source or target is a character device (printer), an asynchronous communication device, or NULL. You must specify a file or block device as your source and your target.

Warning: CHKDSK was unable to return to a parent directory while checking the tree structure. CHKDSK attempts to return to the parent directory by starting over at the root and repeating the search.

Error: While using MODE, you selected a code page not yet prepared for the system or without the correct font to support the current video mode. To correct this error, prepare a code page using the MODE PREPARE command. If you have installed the DISPLAY.SYS installable device driver, make sure that the DEVICE command line in your CONFIG.SYS file allows additional subfonts.

Information: This message displays the code page currently in use by the specified device. If you type MODE CON, for example, the message returns the code page in use for your screen.

Error: While using CHCP, you selected a code page not currently supported by a device. To correct this error, first make sure that your device supports code page switching and that it is online. Then issue the MODE PREPARE command to ready the device for the code page. You are ready to retry CHCP.

Error: CHCP is unable to select a code page for the system. If NLSFUNC is installed and your CONFIG.SYS file does not install device drivers, you can retry CHCP. If CONFIG.SYS installs device drivers, you must issue the MODE PREPARE command to prepare the specific code page for each device before retrying the CHCP command.

Error: While using MODE, you selected a device and code page combination not recognized by DOS. Make sure that you specified a valid device and code page and that the code page you selected is supported on the device.

Error: You selected an incompatible keyboard code and code page combination. Re-enter the KEYB command with a valid keyboard code and code page.

Error: You issued the KEYB command with an unrecognized code page. Prepare the code page for your CON (console screen device) by using the MODE PREPARE command; then retry KEYB.

Warning: You used KEYB with an option incompatible with the code page for your console screen device. Specify a compatible option or issue the MODE SELECT command to change the code page for your console screen device.

Error: You attempted to use a duplicate code page for the specified device; or with MODE PREPARE, you specified more code pages than DOS supports for that device. Check CONFIG.SYS to see how many prepared code pages your device command line allows or issue MODE /STATUS at the command line to view the code pages already prepared for the device (for example, MODE /STATUS CON).

Information: The files you are comparing are not the same. The difference occurs xxxxxxxx bytes from the beginning of the file. The number of bytes and the values for the differing bytes are given in hexadecimal format (base 16).

Information: DISKCOMP has located a difference on the disk in the specified drive on side s at track t.

Error: A fatal error occurred during the comparison operation.

Information: This message confirms the format of the disks you are comparing.

Error (startup): DOS could not load because you set too many files or buffers in your CONFIG.SYS file or specified too large an environment area (/E) with the SHELL command. This problem occurs only on systems with less than 256KB.

Restart DOS with a different configuration; then edit the CONFIG.SYS file on your boot disk, lowering the number of files, buffers, or both. You also can edit CONFIG.SYS to reduce the size of the environment in addition to or as an alternative to lowering the number of files and buffers. Restart DOS with the edited disk.

Another alternative is to increase the RAM in your system.

Error: The original contents of the destination file for the COPY (concatenation) operation were overwritten because the destination and one of the source files had the same name. You might be able to recover the file by using UNDELETE; if not, you can restore the destination file from your backup disk.

Error: The DISKCOPY process ended before completion. Test with SCANDISK or CHKDSK and then copy the remaining files onto the disk with COPY or XCOPY.

Information: You issued the MODE command and specified a device with code page support. MODE displays the active code page, the hardware code page, other prepared code pages, and the space available for additional code pages on the lines that follow the message. If you want to see status information for all devices, type MODE without listing a device.

Information: This message displays the current keyboard code and code page along with the current code page used by the console screen device (CON).

Warning: The system prompt includes the meta-symbol $p, to display the current directory, or $n, to display the current drive. You tried to change the default drive to an invalid drive. (You tried to make a floppy drive current, for example, without a floppy present.) DOS presented the Abort, Retry, Fail? prompt. When you responded by pressing F, DOS temporarily changed the prompt to the Current drive is no longer valid message.

The invalid drive error also occurs when a current networked or substituted disk drive is deleted or disconnected. Simply change the current drive to a valid disk drive.

Error: You selected a code page incompatible with the current keyboard code. First, check the selected code page. If the code page is correct, change the keyboard code by using KEYB.

Error: No code page is present for this device.

Error (startup): An error occurred when DOS tried to load into memory. The disk contained IO.SYS and MSDOS.SYS, but one of the two files could not be loaded.

Try starting DOS from the disk again. If the error recurs, try starting DOS from a disk you know is good, such as a copy of your DOS startup or master disk. If DOS still fails to boot, you have a disk drive problem. Contact your dealer.

Error: EDLIN cannot save your work to disk because the designated disk is full. Always make sure that you have a disk with plenty of room to save your files.

Warning: FORMAT detected one or more bad sectors on the floppy disk in the area where DOS normally resides. Because the portion of the disk where DOS must reside is unusable, you cannot boot DOS from this disk.

Try reformatting the disk. Some floppy disks format successfully the second time. If FORMAT gives this message again, you cannot boot from the disk.

Error: DOS aborted a program that attempted to divide by zero. The program was incorrectly entered or contains a logic flaw. If you wrote the program, correct the error and try the program again. If you purchased the program, report the problem to the dealer or publisher.

This message also might appear when you attempt to format a RAM disk with DOS 3.0 or 3.1. Make sure that you are formatting the correct disk and try again.

Error: You typed an incorrect switch or added one or more filenames with the DISKCOMP command. DISKCOMP syntax does not accept filenames on the command line.

Error: You added an incorrect switch to the command or placed a filename in the command string. Retype the command and press Enter.

Information: Most of the DOS system can be optionally loaded above the first megabyte in the high memory area (HMA), if you have at least a 286, have some available extended memory, and use the DOS=HIGH parameter in CONFIG.SYS. These messages tell you whether DOS is in HMA.

Error: When you are using the DOS editor, this message indicates a serious memory error. If possible, save your work to a different file and reboot your computer.

Error: INTERLNK found a syntax error in its command line. Double-check the syntax by entering HELP INTERLNK.

Error: When using DISKCOMP or DISKCOPY, you specified two drives of different capacities. You cannot use DISKCOMP or DISKCOPY, for example, from a 1.2MB drive to a 360KB drive. Retype the command using compatible drives.

Error: While using RENAME (or REN), you attempted to change a filename to a name that already exists, or the file to be renamed did not exist in the directory. Check the directory to make sure that the filename exists and that you have spelled it correctly. Then try again.

Warning: You are attempting to format a hard disk that has a volume label. Enter the exact volume label to proceed with the format; if you do not want to enter a volume label, press Enter and FORMAT will quit.

Warning (startup): The COUNTRY command in CONFIG.SYS is improperly phrased or has an incorrect country code or code page number. DOS continues to load but uses the default information for the COUNTRY command.

After DOS has started, check the COUNTRY line in your CONFIG.SYS file. Make sure that the command is correctly phrased (with commas between the country code, code page, and COUNTRY.SYS file) and that any given information is correct. If you detect an error in the line, edit the line, save the file, and restart DOS.

If you do not find an error, restart DOS. If the same message appears, edit CONFIG.SYS. Re-enter the COUNTRY command and delete the old COUNTRY line. The old line might contain some nonsense characters that DOS can see but that are not apparent to your text-editing program.

Error: DOS detected an error while attempting to load a program stored in an EXE file. The problem, which is in the relocation information DOS needs to load the program, might occur if the EXE file has been altered.

Restart DOS and try the program again, this time using a backup copy of the program. If the message appears again, the program is flawed. If you are using a purchased program, contact the dealer or publisher. If you wrote the program, issue LINK to produce another copy of the program.

Error (startup): A disk error occurred when DOS was loading from the hard disk. DOS does not start.

Restart the computer. If the error occurs after several tries, restart DOS from the floppy disk drive. If the hard disk does not respond (that is, you cannot run DIR or CHKDSK without getting an error), you have a problem with the hard disk. Contact your dealer. If the hard disk does respond, place another copy of DOS on your hard disk by using SYS. You also might need to copy COMMAND.COM to the hard disk.

Increase to 15 or 20 the number of FILES in the CONFIG.SYS file of your startup disk. Restart DOS. If the error recurs, you might have a problem with the disk. Try a backup copy of the program. If the backup works, copy the backup over the offending file.

If an error occurs in the copying process, you have a flawed disk. If the problem is a floppy disk, copy the files from the flawed disk to another disk and reformat or discard the original disk. If the problem is the hard disk, immediately back up your files and run RECOVER on the offending file. If the problem persists, your hard disk might be damaged.

Error: During a FORMAT procedure, DOS was unable to read the directory; bad sectors might have developed in the file allocation table (FAT) structure.

If the message occurs when DOS is reading a floppy disk, the disk is unusable and should be thrown away. If DOS cannot read your hard disk, however, the problem is more serious, and you might have to reformat your disk. Remember to back up your data files regularly to prevent major losses.

Error: DOS could not read from (or write to) the disk's partition table during the FORMAT operation because the partition table is corrupted. Run FDISK on the disk and reformat the disk.

Error: INTERSVR has detected that the remote system (the one running INTERLNK) has a write error. The most likely reason is that the remote disk is full.

Error: COMMAND.COM has detected an error but cannot tell you the normal error message because the disk containing COMMAND.COM is missing. (This error doesn't generally occur on a hard disk system.) To avoid these anonymous errors, use the /MSG switch on the SHELL= line of CONFIG.SYS.

Warning: DOS encountered a problem in the file allocation table of the disk in drive d. Press R to retry several times; if the message recurs, press A to abort.

CHKDSK can't repair this type of error in the file allocation table. If you have DOS 6.2, SCANDISK might be capable of correcting this problem for you. Commercial third-party utility packages often include tools that can repair this problem as well. Otherwise, you will be forced to back up as many files as you can and then reformat the disk. If FORMAT finds no errors, you can safely go back to using the disk.

Error: You attempted to copy a file to a disk and directory containing the same filename. This error often occurs when you misspell or omit parts of the source or destination drive, path, or filename. This error might occur also when you are using wildcard characters for filenames or when you use SUBST. Check your spelling and the source and destination names, and then try the command again.

Error: A program or DOS failed to add a new file to the directory or to replace an existing file.

If the file already exists, issue the ATTRIB command to check whether the file is marked as read-only. If the read-only flag is set and you want to change or erase the file, remove the read-only flag with ATTRIB; then try again. If the problem occurs when the read-only flag is not set, run SCANDISK or CHKDSK without the /F switch to determine whether the directory is full, the disk is full, or some other problem exists with the disk.

Error: DOS could not find the specified file. The file is not on the current disk or directory, or you specified the disk drive name, pathname, or filename incorrectly. Check these possibilities and try the command again.

Warning (startup): In CONFIG.SYS, the parameters in the device driver filename or the syntax of the DEVICE line is incorrect. Check for incorrect parameters and phrasing errors in the DEVICE line. Edit the DEVICE line in the CONFIG.SYS file, save the file, and restart DOS.

Error: One of these messages might appear when you issue DISKCOMP. The messages indicate that the FIRST (source) or the SECOND (target) floppy disk is unreadable or that the disks you are attempting to compare have different format densities.

Error: You cannot use the FORMAT command on the specified drive. If you entered device driver parameters that your computer cannot support, DOS displays this message. Check CONFIG.SYS for bad DEVICE or DRIVPARM commands.

Information: DISKCOPY displays this message as it copies data to an unformatted disk.

Error: DOS does not recognize the device name you entered with the MODE command.

Error: The copy of the file holding the command you just entered is from a different version of DOS.

Get a copy of the command from the correct version of DOS (usually from your copy of the DOS startup or master disk) and try the command again. If the disk you are using has been updated to hold new versions of DOS, copy the new versions over the old ones.

Prompt: DOS attempted to execute the next command from a batch file, but the disk holding the batch file is not in the disk drive. This message occurs for DOS 3.1 and later versions. DOS 3.0 gives a fatal error when the disk is changed.

Prompt: DOS needs to reload COMMAND.COM but cannot find it on the startup disk. If you are using floppy disks, the disk in drive d (usually A) has probably been changed. Place a disk with a good copy of COMMAND.COM in drive d and press a key.

Prompt: On a system with one floppy disk drive or a system in which DRIVER.SYS creates more than one logical disk drive from a physical disk drive, you or one of your programs specified a tandem disk drive x (such as A or B) that is different from the current disk drive.

If the correct disk is in the disk drive, press a key. Otherwise, insert the correct disk into the floppy disk drive and then press a key.

Warning, Error: The disk does not have enough free space to hold the file being written. All DOS programs terminate when this problem occurs, but some non-DOS programs continue.

If you think that the disk should have enough room to hold the file, run SCANDISK or CHKDSK to determine whether the disk has a problem. When you terminate programs early by pressing Ctrl+Break, DOS might not be capable of doing the necessary cleanup work, leaving some disk space temporarily trapped. SCANDISK or CHKDSK can free these areas.

If you have simply run out of disk space, free some disk space or insert a different disk; then try the command again.

Warning: Your DOSKey macros have filled the total space set aside for them. You must enlarge the memory area for macros (the default is 512 bytes) by using the BUFSIZE switch before you can enter any new macros.

Error: DOS cannot create or write to one or both of the intermediate files it uses when piping information between programs because the disk is full, the root directory of the current disk is full, or the TEMP environment variable points to an illegal path. The most frequent cause is insufficient disk space.

Run DIR on the root directory of the current disk drive to make sure that you have enough room in the root directory for two additional files. If you do not have enough room, make room by deleting or copying and deleting files. You also can copy the necessary files to a different disk that has sufficient room.

This error also might occur if a program is deleting files, including the temporary files DOS creates. In this case, correct the program, contact the dealer or program publisher, or avoid using the program with piping.

Error: Your programs and DOS have exhausted the stack, which is the memory space reserved for temporary use. This problem is usually caused by a rapid succession of hardware devices demanding attention. DOS stops, and the system must be turned off and on again to restart DOS.

The circumstances that cause this message are generally infrequent and erratic, and they might not recur. If you want to prevent this error from occurring, add the STACKS command to your CONFIG.SYS file. If the command is already in your CONFIG.SYS file, increase the number of stacks specified.

Warning: You have selected an illegal baud rate for either INTERLNK or INTERSVR. For example, you have /BAUD:9200 instead of /BAUD:9600.

Error: You attempted to enter more than 11 alphanumeric characters, or you entered illegal characters (+, =, /, , and |, for example) when you typed the disk's volume label (the disk name). Retype the volume label with valid characters.

Warning: DOS tried to reload COMMAND.COM from the disk in drive d and found that the file was from a different version of DOS. Follow the instructions for inserting a disk with the correct version.

If you frequently use the disk that generated this warning message, copy the correct version of COMMAND.COM to that disk.

Error: DOS could not find COMMAND.COM on the hard disk. DOS halts and must be restarted.

COMMAND.COM might have been erased, or the COMSPEC variable in the environment might have been changed. Restart the computer from the hard disk. If a message indicates that COMMAND.COM is missing, the file was erased. Restart DOS from a floppy disk and copy COMMAND.COM to the root directory of the hard disk or to the location your SHELL command indicates, if you have placed this command in your CONFIG.SYS file.

If you restart DOS and this message appears later, a program or batch file is erasing COMMAND.COM or altering the COMSPEC variable. If a program is erasing COMMAND.COM, contact the dealer or publisher who sold you the program. If a batch file is erasing COMMAND.COM, edit the batch file. If COMSPEC is being altered, edit the offending batch file or program, or place COMMAND.COM in the subdirectory your program or batch file expects.

Warning (startup): The COUNTRY code number or the code page number given to the COUNTRY command in CONFIG.SYS is incorrect or incompatible. DOS ignores the COUNTRY command and continues the startup process.

Check the COUNTRY command in your CONFIG.SYS file (see Chapter 14, “Understanding the International Features of DOS”) to determine whether the correct and compatible country code and code page numbers are specified. If you detect an error, edit and save the file. Then restart DOS.

Error: You gave an impossible date or an invalid character to separate the month, day, and year. This message also appears if you enter the date from the keypad when it is not in numeric mode.

Error: The partition did not fall on a track boundary. You might have set the DEVICE drivers incorrectly in CONFIG.SYS or attempted to format a hard disk formatted with DOS 2.x so that the total number of hidden sectors is not evenly divisible by the number of sectors on a track. Therefore, the partition might not start on a track boundary.

To correct the error, run FDISK before formatting or check CONFIG.SYS for a bad DEVICE or DRIVPARM command.

Error: You specified a directory name that does not exist, you misspelled the directory name, the directory path is on a different disk, you did not give the path character () at the beginning of the name, or you did not separate the directory names with the path character. Check your directory names to make sure that the directory exists and try the command again.

Warning: A floppy disk was changed while a program had open files to be written to the floppy disk. Place the correct disk in the disk drive and press R to retry. Typically, this check is supported on drives larger than 360KB.

Warning: You specified an invalid disk drive name in the PATH command, or a disk drive you named is nonexistent or hidden temporarily by a SUBST or JOIN command.

Use PATH to check the paths you instructed DOS to search. If you gave a nonexistent disk drive name, issue the PATH command again with the correct search paths. If the problem is temporary because of a SUBST or JOIN command, you can run PATH, leaving out or correcting the wrong entry. Or you can just ignore the warning message.

Error: You gave the name of a nonexistent disk drive, or you mistyped the disk drive or filename.

Remember that certain DOS commands (such as SUBST and JOIN) temporarily hide disk drive names while the command is in effect. Check the disk drive name you gave and try the command again.

Error: You entered an invalid or nonexistent disk drive as a parameter to a command; you specified the same disk drive for the source and destination; or by not giving a parameter, you defaulted to the same disk drive for the source and the destination.

Remember that some DOS commands (such as SUBST and JOIN) temporarily hide disk drive names while the command is in effect. Check the disk drive names. If the command is objecting to a missing parameter and defaulting to the wrong disk drive, name the correct disk drive explicitly.

Error: You gave the name of a nonexistent disk drive, you named the hard disk drive when using commands for only floppy disks, you did not give a disk drive name and defaulted to the hard disk when using commands for only floppy disks, or you named or defaulted to a RAM disk drive when using commands for a floppy disk.

Remember that certain DOS commands (such as SUBST and JOIN) temporarily hide disk drive names while the command is in effect. Check the disk drive name you gave and try the command again.

Error: You selected an invalid code. Enter the KEYB command again with the correct keyboard code.

Error: You entered an illegal character or command with DOSKey or attempted to create a DOSKey macro with an illegal definition. This message appears, for example, if you use a GOTO command in a DOSKey macro. Correct any errors and carefully retype the macro.

Error: A disk you are trying to format might be damaged. A disk might not format the first time. Try to format again; if the same message appears, the disk is bad and should be discarded. With some versions of FORMAT, this same symptom can be caused by memory boundary problems. If the symptom occurs for multiple floppy disks, try changing the number or sizes of TSRs to see whether the symptoms change.

Error: You have given too few or too many parameters to a command. One of the following occurred: You omitted required information, you omitted a colon immediately after the disk drive name, you inserted an extra space, you omitted a required space, or you omitted a slash (/) in front of a switch.

Error: At least one parameter you entered for the command is not valid. One of the following occurred: You omitted required information, you omitted a colon immediately after the disk drive name, you inserted an extra space, you omitted a required space, you omitted a slash (/) in front of a switch, or you used a switch the command does not recognize. For more information, check the explanation of this message in the “Command Reference” for the command you issued.

You typed conflicting parameters with a DOS command. Retype the command with only one of the conflicting switches.

Error (startup): DOS has detected a problem in the hard disk's partition information. Restart DOS from a floppy disk. Back up all files from the hard disk, if possible, and run FDISK to correct the problem. If you change the partition information, you must reformat the hard disk and restore all its files.

Error: The pathname contains illegal characters, the pathname has more than 63 characters, or a directory name within the path is misspelled or does not exist.

Check the spelling of the pathname. If necessary, check the disk directory with DIR to make sure that the directory you have specified exists and that you have specified the correct pathname. Make sure that the pathname contains no more than 63 characters. If necessary, change the current directory to a directory closer to the file to shorten the pathname.

Error: You gave a directory name or filename that does not exist, specified the wrong directory name (a directory not on the path), or mistyped a name. COPY aborts when it encounters an invalid path or filename. If you specified a wildcard for a filename, COPY transfers all valid files before it issues the error message.

Check to see which files have been transferred. Determine whether the directory and filenames are spelled correctly and whether the path is correct. Then try again.

Warning (startup): One of the following problems exists with the STACKS command in your CONFIG.SYS file. A comma is missing between the number of stacks and the size of the stack, the number of stack frames is not in the range of 8 to 64, the stack size is not in the range of 32 to 512, you have omitted the number of stack frames or the stack size, or the stack frame or the stack size (but not both) is 0. DOS continues to start but ignores the STACKS command.

Check the STACKS command in your CONFIG.SYS file. Edit and save the file; then restart DOS.

Error: You gave an impossible time or invalid character to separate the hours, minutes, and seconds. This message also appears if you enter the time from the keypad when it is not in numeric mode.

Error: When formatting a fixed (or hard) disk, you entered an incorrect volume label, and DOS aborted the format attempt. Type VOL at the DOS prompt and press Enter to view the volume label of the disk; then try the command again.

Error: A program destroyed the area where DOS keeps track of memory. You must restart DOS. If this error occurs again with the same program, the program has a flaw. Try a backup copy of the program. If the problem persists, contact the dealer or program publisher.

Error (startup): The DOS hard disk partition entry is marked as bootable (capable of starting DOS), but the DOS partition does not contain a copy of DOS. DOS does not start.

Start DOS from a floppy disk. Issue the SYS C: command to place DOS on the hard disk and then copy COMMAND.COM to the disk. If this command fails to solve the problem, you must back up the existing files, if any, from the hard disk; then issue FORMAT /S to place a copy of the operating system on the hard disk. If necessary, restore the files you backed up.

Error: MSBACKUP relies on repeated access to its program files during the backup operation. You must start it from a hard disk so that the program files will be available throughout the process. Change the default drive to the hard disk before starting MSBACKUP.

Error: On FORMAT, you must specify /T (number of tracks per side) and /N (number of sectors per disk) on the same command line. If you include the one, you must include the other.

Error: You must specify COM1, COM2, COM3, or COM4 when using this form of the MODE command.

Information: INTERLNK isn't currently redirecting any drive letters to the remote system.

Error: DOS could not load an additional copy of COMMAND.COM because no file handles were available. Edit the CONFIG.SYS file on your startup disk to increase by five the number of file handles (using the FILES command). Restart DOS and try the command again.

Information: INTERLNK isn't currently redirecting any printer ports to the remote system.

Error: This error isn't nearly so prevalent in DOS 6.0 or 6.2 as it was in previous versions. SYS rearranges the files as needed to make a system bootable but issues this error if insufficient room is available or if the root directory is full.

Error: You specified the /COM switch on INTERSVR, but no serial ports are available. This problem could occur if a TSR program has taken control of the available port or if the hardware is configured to an invalid address.

Error: SYS cannot find the system files. Insert a disk containing the system files, such as the DOS disk, and type the command again. If the system files are available on another drive, issue the other form of the SYS command, indicating the location of the system files.

Error (startup): Your disk does not contain IO.SYS and MSDOS.SYS, or a read error occurred when you started the system. DOS does not start.

If you are using a floppy disk system, insert a bootable disk into drive A and press a key. The most frequent cause of this message on hard disk systems is leaving a nonbootable disk in drive A with the door closed. Open the door to disk drive A and press a key. DOS boots from the hard disk.

Error: The computer does not have enough free RAM to execute the program or command. If you loaded a resident program, such as PRINT, GRAPHICS, SideKick, or ProKey, restart DOS and try the command again before loading any resident programs. If this method fails to solve the problem, remove any nonessential device drivers or RAM disk software from CONFIG.SYS and restart DOS. If this option also fails, your computer does not have enough memory for this command. You must increase the amount of RAM installed in your computer to run the command.

Warning: Not enough room is available in the current environment to add (or change) the variables you have specified with the SET, PATH, or PROMPT command. If you are running SET, PATH, or PROMPT from a shell program such as DOS Shell, quit the shell program and try the command again. If the command still fails, you can increase the size of the environment by increasing the /E:size parameter for the SHELL= command in your CONFIG.SYS file and restarting your computer.

Error: The amount of memory is insufficient to perform the operation you requested. This error occurs in the DOS 5.0 Editor.

Error: The program appears to be damaged. A common cause of this symptom is older format-packed executables, which could not load into the first 64KB of conventional memory. With older operating system versions, the resident portion of the system generally used enough memory that this wasn't a problem. In DOS 5.0, 6.0, and 6.2, the DOS=HIGH, DEVICEHIGH, and LOADHIGH features can reduce memory usage enough that this problem occurs with certain programs. Use the LOADFIX command to use up enough memory temporarily so that the program is loaded at a location it can manage.

Error: You entered parameters that do not exist, that are not supported by the DOS version you are running, or that are incompatible with the specified disk drive. Run VER to determine whether the current DOS version supports the parameters (or switches) you specified.

Error: A device driver for a hard disk does not support generic IOCtl functions.

Error: COMMAND.COM has detected an error but cannot tell you the normal error message because the floppy disk containing COMMAND.COM is missing. (This error doesn't generally occur on a hard disk system.) To avoid these “anonymous” errors, use the /MSG switch on the SHELL= line of CONFIG.SYS.

Error: A specified file or directory path does not exist. You might have misspelled the filename or directory name, or you might have omitted a path character () between directory names or between the final directory name and the filename. Another possibility is that the file or directory does not exist in the place specified. Check these possibilities and try again.

Error: You have given a pathname that exceeds the DOS 64-character limit, or you omitted a space between filename parameters. Check the command line. If the phrasing is correct, you must change to a directory closer to the file you want and try the command again.

Error: The computer does not have enough memory to load the program or command you invoked. If you have any resident programs loaded (such as PRINT, GRAPHICS, or SideKick), restart DOS and try the command again without loading the resident programs. If this message appears again, reduce the number of buffers (BUFFERS) in the CONFIG.SYS file, eliminate nonessential device drivers or RAM disk software, and restart DOS. If the problem persists, your computer does not have enough RAM for the program or command. You must increase the amount of RAM in your computer to run the program.

Error: Many DOS commands give this error when you omit part of the parameter list. You might have specified only a single name with the MOVE command, for example.

Error: You duplicated a switch when you typed a command. Retype the command using the parameter only once.

Error: The device driver filename that you are loading in your CONFIG.SYS file with a DEVICE= or DEVICEHIGH= command uses a sector size that is too large. You cannot use this device driver.

Error: The disk you attempted to read during a copy process was damaged or in the wrong format (for example, a high-density disk in a double-density disk drive). DOS cannot read the disk.

Error: The port number is legal, but your ROM BIOS doesn't support it. Generally, this problem can happen with an older BIOS that supports only two COM ports. Either replace the computer's ROM BIOS or specify COM1 or COM2.

Error: You phrased a command improperly by omitting needed information, giving extraneous information, inserting an extra space into a file or pathname, or using an incorrect switch. Check the command line for these possibilities and try the command again.

Error: A problem exists with the target disk. DOS does not recognize the format of the target disk in the drive, or the disk is defective. Make sure that the target disk is the same density as the source disk, run SCANDISK or CHKDSK on the target disk to determine the problem, or try to reformat the disk before proceeding with the disk copy operation.

Warning: The target disk can hold fewer bytes of data than the source disk. The most likely cause is bad sectors on the target disk. If you press Y, some data on the source disk might not fit on the target disk.

To avoid the possibility of an incomplete transfer of data, press N and insert a disk with the same capacity as the source disk. If you are not copying “hidden” files, you also can issue the COPY *.* command to transfer files.

Error: INTRSVR cannot find any serial ports or parallel ports not already in use. Without such a port, INTRSVR cannot communicate with INTRLNK.

Warning: The disk lacks sufficient room to create a restore file. Without this file, you cannot use UNFORMAT to reverse the format you are attempting.

Error: At the DOS prompt, you tried to run a program that needs Microsoft Windows to execute. If you are already running Windows, press Alt+Tab to switch to the Program Manager and start it from there. If you haven't started Windows, use WIN to do so.

Warning (startup): Your CONFIG.SYS file contains too many DEVICE commands. DOS continues to start but does not install additional device drivers.

DOS can handle only 26 block devices. The block devices created by the DEVICE commands plus the number of block devices automatically created by DOS exceed this number. Remove any unnecessary DEVICE commands from your CONFIG.SYS file and restart DOS.

Warning: INTERLNK cannot automatically scan this many parallel ports. The earlier ones will be used.

Warning: INTERLNK cannot automatically scan this many serial ports. The earlier ones will be used.

Error (startup): COMMAND.COM or another DOS command detected a disk error, and you chose the A (abort) option. DOS cannot finish starting itself, and the system halts.

Try to start DOS again. If the error recurs, start DOS from a floppy disk (if starting from the hard disk) or from a different floppy disk (if starting from a floppy disk). After DOS has started, issue the SYS command to place another copy of the operating system on the disk and copy COMMAND.COM to the disk. If DOS reports an error while copying, the disk is bad. Reformat or discard the floppy disk or back up and reformat the hard disk.

Information, Warning: A bad allocation unit was found when the FORMAT command executed.

Error: MOVE was unable to create the destination file. Possible reasons are that the destination drive is full or that the destination is the root directory, which lacks room.

Error: You or a program could not create a directory for one of the following reasons. A directory by the same name already exists; a file by the same name already exists; you are adding a directory to the root directory, and the root directory is full; or the directory name has illegal characters or is a device name.

Issue DIR to make sure that no file or directory already exists with the same name. If you are adding the directory to the root directory, remove or move (copy and then erase) any nonessential files or directories. Check the spelling of the directory name and make sure that the command is properly phrased.

Error: INTRSVR was unable to initialize the specified serial port. The most common reason is that two devices in the system have the same port address.

Error, Prompt: DOSSHELL.COM could not load DOSSHELL.EXE. Normally, this error is caused by not having enough conventional memory. If you are attempting to run DOSSHELL from another program, quit the program and try again.

A less likely cause for this error message is that the DOSSHELL.EXE file is corrupted. If you have plenty of conventional memory available (MEM /FREE), get a fresh copy of DOSSHELL.EXE from a backup disk.

Error: MOVE was unable to open the specified source file. This problem could be the result of an illegal character used in the filename, but the more common cause is trying to move a directory to a different place in the disk hierarchy. You can rename a directory by using the MOVE command but not actually move it.

Error: A disk problem occurred while transferring the data from the source file to the destination. Use COPY to copy the file, compare it, and then delete the original.

Error: FORMAT cannot write to the BOOT track or DOS partition of the disk that is being formatted because one of these areas is bad. Discard the bad disk, insert another unformatted disk, and try the FORMAT command again.

Error: A disk problem occurred while transferring the data from the source file to the destination. Double-check that the destination disk has sufficient room for the file. If the error still occurs, use COPY.

Warning (startup): DOS detected an improperly phrased command in CONFIG.SYS. The command is ignored, and DOS continues to start. Examine the indicated line in the CONFIG.SYS file, looking for an improperly phrased or incorrect command. Edit the line, save the file, and restart DOS.

Error: You tried to use a switch that was illegal for the particular internal command. Type the command followed by /? to find out what options are permitted.

Error: DOS was unable to read the data at the specified location on the disk. DOS makes four attempts before generating this message. Copy all files on the questionable disk to another disk and try the command again, first with a new disk and then with the backup disk. If the original disk cannot be reformatted, discard it.

Error: INTRSVR is getting excessive errors on the communications cable to INTERLNK. Check that the connections are screwed in tightly and that the cable is not routed too close to electrical interference, such as an arc welder.

Error: DOS was unable to write to a disk at the location specified. Try the command again; if the error recurs, the target disk is damaged at that location. If the damaged disk contains important data, copy the files to an empty, freshly formatted disk and try to reformat the damaged disk. If the disk is bad, discard it.

Warning: You specified a drive that SMARTDRV cannot cache, such as a network drive. The version of SMARTDRV distributed with DOS 6.2 can cache CD-ROM drives, but previous versions cannot. SMARTDRV ignores this drive letter.

Error: The disk you are writing to has bad sectors in the boot sector or file allocation table (FAT). Run SCANDISK if you have DOS 6.2 to see whether the error can be corrected. If the disk is a floppy, you should probably discard it.

Warning: INTERLNK cannot permit certain operations to occur while it is in control. One of these is the DOSSHELL capability to switch tasks. If INTERLNK was swapped while communicating with INTERSVR, you might lose data. INTERLNK therefore inhibits these operations until it is complete.

Error: SMARTDRV must be given the host drive letter to cache. The compressed drive also is cached, and the effective cache size is increased because of the compression. You cannot separately cache the compressed drive.

Error: This error message is uncommon. A software program has issued an invalid or unsupported command to the drive or device indicated. The problem might be with the device driver or software program. If either of them is new to your system, contact the manufacturer of the software to see whether an upgrade is available.

Error: This error message is uncommon. A software program has issued a command to the indicated drive or device, but the command contains an invalid request header. The problem is usually with the software program. Contact the manufacturer of the software to see whether an upgrade is available.

Error: An invalid subunit number was passed to the device driver. This error is displayed if you try to access one of INTERLNK's drives when the drive letter isn't currently redirected to the INTERLNK server. Use the INTERLNK command to link the drive letter to a drive on the server and try again.

Error: DOS was unable to read some of the data on the disk. When this message appears, choose Retry at least two or three times before giving up. Quit the application you are using and run SCANDISK or CHKDSK to attempt to locate and correct the problem on the disk.

Error: An error occurred when DOS tried to read or write to the disk drive. For floppy disk drives, the drive door might be open, the floppy disk might not be fully inserted, or the disk might not be formatted. Correct the situation and choose Retry. For hard disk drives, this error might indicate a hardware problem. If you get this error for a device rather than a disk drive, check to see that the device is turned on and ready to read or write.

Error: A program using file control blocks (FCBs) attempted to open more file control blocks than were specified with the FCBS= command. Usually, you have to choose the Abort option and terminate the program you are using. Increase the value of the FCBS= command in your CONFIG.SYS file by four or five; then reboot the system. If the message appears again, increase the value again and reboot.

This method of opening files dates back to DOS 1 and CP/M and should not be used by any current programs that you work with.

Error: This message is a catchall for errors not covered elsewhere and can occur with disk drives or other devices. Whenever a device driver is unsure of what to call the error it has just received, it calls the error a general failure. Reading disks formatted for operating systems other than DOS can often result in a general failure message.

If you load the file-sharing SHARE.EXE program into memory, you might see this message more often. SHARE prevents two programs from opening the same file at the same time. Newer programs recognize that SHARE is denying them access, but others might return general failure messages. If you are running Windows and receive this message in a DOS program, don't panic. It probably means that another application has a file open, and you are being denied access.

Error: With a file-sharing program such as SHARE.EXE or network software loaded, a program attempted to access a locked file. Your best choice is Retry. If you are on a network, get a cup of coffee and choose Retry again to see whether the other user has released the lock yet. If you just can't seem to get access to the file, choose Fail. The program you are using might notice the failure and ask you what to do about it. The last resort is to choose Abort, but be aware that any unsaved data in memory will be lost when the program is terminated.

Error: With a file-sharing program such as SHARE.EXE or network software loaded, a program attempted to access a file that is in use by another program. Your best choice is Retry. If you are on a network, get a cup of coffee and then choose Retry again to see whether the file is available yet. If you can't get access to the file, choose Fail. The program you are using might notice the failure and ask you what to do about it. The last resort is to choose Abort, but be aware that any unsaved data in memory will be lost when the program is terminated.

Error: The printer is out of paper (or not turned on). Check your printer, add paper, make sure the printer is online, and choose Retry. The message DOS displays stays on the screen waiting for you to make a choice, so you could go across town and buy paper if you need to.

Error: The boot sector or the file allocation table (FAT) of the disk contains invalid information, making the disk unusable. If you come into contact with computers using operating systems other than DOS, you might be trying to read one of their disks.

When you are sure that the disk is a DOS disk, run SCANDISK or CHKDSK to see whether it can be repaired. Even if the repair is successful, you should back up all the files on the disk and reformat it. If FORMAT finds no errors, you can safely begin using the disk again.

Error: This error message is common. It usually means that you've left open the door to your floppy disk drive. Other common causes are that the drive is empty or the disk isn't seated properly. Check the drive or reinsert the disk, and then choose Retry. If you can't get a floppy disk drive to read any disks that you put in it, you might have a hardware problem.

Error: DOS was unable to read data from the drive. Often this problem is caused by a floppy disk that isn't seated properly in the drive, or you might have a bad spot on the disk. Reinsert the disk and choose Retry. Usually, the read operation succeeds after you choose Retry a few times. Check the disk by running SCANDISK to make sure that no errors appear on it, or back up any files and reformat the disk.

If you begin to get several of these errors, your floppy disk drive might be out of alignment. When this problem occurs, people typically start complaining that they can't read your disks. If your drive is out of alignment, your only options are to repair or replace the drive.

Error: The disk drive was unable to find the requested sector on the disk. This error is usually the result of a defective spot on the disk. Choose Retry quite a few times before you give up; often the sector will be found if you're persistent. Check the disk by running SCANDISK to make sure that no errors appear on it, or back up any files and reformat the disk.

Some copy-protection schemes use a defective spot to prevent unauthorized duplication of the disk. If you have reason to believe that the disk you are reading or writing to is copy-protected, do not correct the disk by running SCANDISK. Contact the manufacturer of the copy-protected software and ask for a replacement disk.

Error: The disk drive could not find the proper track on the disk. Seek errors are often the result of failing drive electronics. If, however, the disk is not properly seated in the drive, reseating it corrects the problem. Choose Retry a few times to see whether the problem goes away. If you are having a hardware problem, you will get more of these errors as time goes on and will eventually have to repair or replace your disk drive.

Error: DOS was unable to write data to the drive. Often this problem is caused by a floppy disk that isn't seated properly in the drive, or you might have a bad spot on the disk. Reinsert the disk and choose Retry. The write operation usually succeeds after you choose Retry a few times. Check the disk by running SCANDISK to make sure that no errors appear on it, or back up any files and reformat the disk.

If you begin to get several of these errors, your floppy disk drive might be out of alignment. When this problem occurs, people typically start complaining that they can't read your disks. If your drive is out of alignment, your only options are repair or replacement.

Error: DOS could not write the data to this device. This error typically is caused by not having your printer turned on or online, although the same thing can happen with an external modem. Check the device and choose Retry. If the problem persists, you might have a faulty cable.

Error: DOS attempted to write to a disk that is write-protected. If the disk is a floppy and the write operation is intentional, remove the disk, adjust the write-protect tab, and reinsert the disk. Don't switch floppy disks at this prompt. To allow the write operation to proceed, make sure that the disk is no longer write-protected and choose Retry. If you don't want to allow the program to write to the disk, choose Fail or, as a last resort, Abort. Remember that if you choose Abort, any unsaved data in memory will be lost.

Error: You have removed a disk that DOS needs access to. This message can occur only with removable media, such as floppy disks. Unfortunately, DOS doesn't tell you what disk it needs; it tells you only the drive. Think back, put the previous disk back in the drive, and choose Retry. Choosing any other option might mean that the disk that was prematurely removed might be damaged or incomplete. Never choose Fail or Abort at this message without first removing all media from the disk drive because DOS could write the wrong file allocation table (FAT) to that disk and destroy all the data on it.