How to put a Terminal Services server in Install mode.
You will need to switch to install mode, to install or remove programs on a terminal server.
The method I use the most is :
Open command prompt as administrator
Type: change user /install
This will change the server to install mode.
Now your ready to install applications.
Switch Terminal Services to Execute Mode, when you are finished adding or removing programs.
Open command prompt as administrator
Type: change user /execute
Users can now log in and start using the new applications