The terminal Server needs to be in Install mode. When you want to add or remove programs, put the Terminal Services server in Install mode. To do this: Click Start, and then click Run. In the Open box, type "cmd" and then click OK. At the command prompt, type "change user /install" and then press ENTER. The following message appears: User session is ready to install applications. Type "exit" and then press ENTER. Add or remove the programs that you want. When you are finished adding or removing programs, return the Terminal Services server to Execute mode. To do this: Click Start, and then click Run. In the Open box, type "cmd" and then click OK. At the command prompt, type "change user /execute" and then press ENTER. The following message appears: User session is ready to execute applications.
Type "exit" and then press ENTER.