The essential goal of troubleshooting is to find the exact location where a known good input results in a bad output. At that point, you've isolated the "bad" component and can then focus on fixing, replacing, or sometimes working around it. Tracking down the problem component among your computers, monitors, printers, and software is often easier said than done! Unless plumes of smoke are pouring from the back of the computer, just knowing where to start looking can be a challenge. The following steps can help you diagnose where things went wrong and perhaps even solve the problem:

Storing catalog backups is just like keeping a fire extinguisher in your kitchen: You kind of forget about it and hope you never have to use it, but if you need it, you're sure glad you had it on hand! You pull a catalog backup off the bench and send it into the game for two main reasons:

The backup catalog created by Lightroom is an exact copy of your working catalog (at that moment in time) and has the same name and file extension of the working catalog. Here are the steps to replace a bad catalog file with a good backup copy:

If you notice a problem with Lightroom the first time you start it, something may have gone wrong during the installation process. Uninstalling and then reinstalling may be all that's required to correct the problem. The process is different for each operating system, so I separated the steps for each.

On Windows:

On a Mac:

Uninstalling Lightroom doesn't touch the catalog file, the preference file, your presets, or your photos. Uninstalling Lightroom removes only the application. When you reinstall, you find all those other files just as you left them. To reinstall on either platform, just double-click the installation file and follow the installation instructions.

This one seems to affect Windows users and is the cause of some frustration because the solution isn't readily apparent. The problem can present itself the first time you try to run a slideshow, or it can present itself after you've used the slideshow successfully for some time. What happens is that you trigger a slideshow to play, and all you see is a black screen. You may see the slides advance in the Filmstrip if you're playing the slideshow in the content area, but the content area is black and stays that way.

The solution in all the cases I've dealt with is to update your video card driver. Go to the Web site of your video card manufacturer and download the latest video card driver for your specific card. The file you download is most likely just like an application you install — double-click it and follow the prompts. Restart your system after the installation is complete. Then recalibrate your monitor, launch Lightroom, and attempt another slideshow.

Another common slideshow-related issue is a slideshow that doesn't play to the end. Instead, the slideshow goes some number of photos in, and then automatically jumps to the beginning and starts over. Subsequent attempts may get a little farther into the show, but then the slideshow still jumps back to the beginning before getting to the end.

Before you get to the end of your rope

The most likely cause for this behavior is that Lightroom hasn't finished rendering the standard-sized previews for that group of photos, so your slideshow displays all the images it has previews for and then jumps back to the start. After all the previews are rendered, the slideshow plays all the way through.

Sometimes as a new user, you enable features without realizing you have and then you're stymied trying to figure out how to get back to the way things were before. I'm the first to admit it's happened to me, and judging by the number of times I see this issue raised, I know I'm in good company.

Lightroom has three screen modes:

You can move through each screen mode by pressing F. Sometimes people inadvertently hit the F key and then find themselves in Full Screen mode and don't know how to get out! You can either continue pressing F to cycle back to Standard Screen Mode or press Ctrl+Alt+F (

The person who coined the phrase no good deed goes unpunished may have done so after having just reorganized her photo library with her file browser of choice (Windows Explorer, Adobe Bridge, or Finder on a Mac) only to open Lightroom and find that all the folders and the thumbnails are all sporting question mark icons.

I don't think a day goes by where someone somewhere doesn't run smack into his own good intentions in this manner. These stories all seem to start the same way ... "I finally decided to organize all my photos" or "I needed to move all my photos to a new drive," and they all end with a new problem to solve.

The nature of the problem is that if you move folders and photos outside Lightroom, Lightroom doesn't know where to find them. All Lightroom knows is what's in its database. If the path in its database doesn't lead to a photo, Lightroom just considers the photo missing until you reconnect it to the photo's new location. The reconnection process isn't difficult but does require that you know where the file or folder is located. Here are the steps to reconnect a folder that's been moved:

If only a few files show question marks, which indicates they're missing, you can reconnect them with a similar process:

Another reason files and folders appear to be missing is that a network or external drive is disconnected. In the case of disconnected media, the solution is to reconnect the drive, and after your computer recognizes the drive, Lightroom finds it, too.

After import, Lightroom goes through the process of rendering preview files of all your imported images. When everything is functioning correctly, you may not notice anything is happening or you may notice that the embedded camera-generated preview file is being replaced by the Lightroom-rendered preview.

When things aren't functioning correctly, you notice that either the previews aren't rendering at all (they just appear as gray or black rectangles) or all the previews have a strange color cast (typically magenta). I've only seen this problem occur on Windows, and both issues are caused by a bad monitor profile.

If you're using a hardware-calibration device, the first thing to do is recalibrate your monitor. This results in a new profile being created and should solve the problem. If you're not using a hardware-calibration device, this might be a sign that it's time to invest in one. In the interim, you can try removing the current default profile to see if that makes a difference. The process is slightly different between Windows XP and Vista.

On Windows XP:

On Vista:

This is an often-asked question that stems from a misunderstanding more than a problem. When you shoot in raw mode, your camera saves that raw data to your memory card without processing it. However, your camera embeds a JPG preview in each raw file — the same JPG preview that you see on the back of your LCD screen. However, Lightroom has to render its previews for every raw file. The result is that while you watch the imported files appear on-screen, you first see the JPG preview you saw on the back of the camera, and then it's replaced by Lightroom's version of the default processing of that raw file. It's very likely that the two versions won't match, and the new Lightroom user's first thought is, "Why is Lightroom destroying my raw files!?"

When the camera renders its JPG preview, it relies on the in-camera settings you applied for color mode, saturation, sharpness, and so on. Your camera may even have some special picture styles or black-and-white mode. Lightroom doesn't have access to any of those in-camera settings. All Lightroom has is the raw capture data and its default rendering instructions for each camera model it supports, which is kind of a recipe for disappointment if you don't know what to expect.

To get around this situation, you can apply a develop preset during import, and Lightroom uses that preset setting to inform its default rendering. Some users shoot in Raw+JPG mode and then import both as individual files. With both versions in Lightroom, they attempt to match the rendering of the JPG and then save those settings as a new Develop preset to be applied at import to raw files. Most of the time, just knowing what to expect can make all the difference. You can find more about the Import process in Chapter 4.

Over time, you may notice that Lightroom isn't as snappy as it used to be (hey, who is?). A decrease in speed as your catalog grows larger and larger is normal, but you can do a few things for your disk and for Lightroom's catalog to keep them both running as smoothly as possible.

Here are some things you can do for your hard disk:

After you do your housekeeping on the startup disk, you can turn your attention to Lightroom:

I hope you see some gains after following these suggestions. If Lightroom is otherwise functioning normally and your system is getting a little long in the tooth, you may want to consider a hardware upgrade in your future.