From http://support.microsoft.com/kb/947723
When you connect to a server that does not have Terminal Server installed.
If a member of the Administrators group starts a Remote Desktop session to a Windows Server 2008-based server that does not have the Terminal Server role service installed, the following conditions are true for the remote administration session:
- Time zone redirection is disabled.
- Terminal Services Session Broker
- (TS Session Broker) redirection is disabled.
- Plug and Play device redirection is disabled.
- The remote session theme is changed to Windows Classic.
- Terminal Services Easy Print is disabled.
When you connect to a server that has Terminal Server installed
If a member of the Administrators group starts a Remote Desktop session to a Windows Server 2008-based server that has the Terminal Server role service installed, they must use the /admin switch to connect to a session to remotely administer the server. The following conditions are true for the session:
- You do not have to have a TS CAL to remotely administer a terminal server.
- Time zone redirection is disabled.
- Terminal Services Session Broker redirection is disabled.
- Plug and Play device redirection is disabled.
- The remote session theme is changed to Windows Classic.
- Terminal Services Easy Print is disabled.