One of our clients Windows 2003 servers was doing strange things, on connecting to the server via Remote Desktop all you got was a blue screen (default windows background colour). My guess was that a session or 2 was still running in the background and needed to be killed off, but because we couldn’t get access to the server via Remote Desktop or physically we had a bit of a problem. Thats when I remembered the following neat trick.
If you pass /console (/admin on newer versions of the Remote Desktop Client) to the Remote Desktop Client (mstc.exe) and then connect to the server you connect to the servers console and not a new terminal server session. I believe there are ways to specify that you want to connect to the console in the hostname field but I haven’t gotten that working yet.
In my case it allowed me to kill off the troublesome Sessions and get access back to the server.
Found this info on this site. (Which BTW is a useful site.)