As soon as you take a Windows Server and turn it into a RDSH server to be used within an RDS environment, the way that applications work on that server changes significantly. Whenever programs and apps are installed onto that RDSH, it first needs to be put into a special Install Mode. Placing the server into Install Mode prior to launching the program installer is important to make sure that applications are going to be installed in a way that will allow multiple users to run them simultaneously. Remember, our RDSH servers will be hosting multiple user sessions, probably dozens of them.
Using Install Mode is so important to applications working properly on an RDSH that you really should not install any programs onto the server before you turn it into an RDSH. Once that role has been established, then apps can be safely installed, as long as you are using Install Mode. Programs installed prior to converting that server into an RDSH may not work properly, and you might have to uninstall and reinstall them. There are a couple of different ways that Install Mode can be invoked during a program installation; let's take a look at both of them.
We need to install a program onto our RDSH server. This box is running Windows Server 2016 and is already part of our RDS environment. We will also need, of course, the application installer files that we intend to launch.
One way to properly install programs onto an RDSH is by using Control Panel to install the application:
- Right-click on your Start flag and choose to open Control Panel.
- Click on Programs.
- Choose the button that says Install Application on Remote Desktop....
- Click Next and you will be able to specify the location of your installer file for the application.
- Click Next, and your program will install. When finished, make sure you click the Finish button on the Install Mode mini-wizard screen, so that the RDSH is placed back into Execute Mode and is ready for normal operation.
The second way to place an RDSH into Install Mode is by using the command prompt:
- Right-click on the Start flag and choose to open Command Prompt (Admin).
- Type
change user /installand press Enter.
- Now find your program installer file and launch it. Walk through the installation steps in the same way you would on any regular server or computer.
- Once the program has finished installing, head back to the command prompt window and now type
change user /execute. Then press Enter. This takes the RDSH out of the special Install Mode and places it back into normal Execute Mode.
When installing applications onto an RDSH, it must first be placed into a special Install Mode. Doing this re-maps certain parts of the program being installed so that it can be run and utilized by many users at the same time. Installing your applications by using one of the methods discussed in this recipe will be critical to the success of your RDS environment being able to provide applications to users.
Also keep in mind that it is recommended you have no users logged into an RDSH during the time of installation. When you are building fresh servers, this is easy as you don't typically allow anyone to connect until everything is installed and configured. But if you need to install new programs or updates to existing programs onto a production RDSH, you will want to take steps to ensure that users are not logged in to the server before you place it into Install Mode and launch those executables. If you are running a farm of RDS servers and want to remove just one or some of them for maintenance or the installation of an application, make sure to check out the Removing an RD Session Host server from use for maintenance recipe.
I mentioned placing the RDSH into Install Mode even when just installing updates to existing applications. This is important. However, you do not need to place a server into Install Mode in order to install regular Windows operating system updates. These are able to install correctly even when the server is in normal Execute Mode.