On the client computer goto start then run and type “mstsc /console” and login to the server.

this will connect you to the console session of Windows Server
2003.  If there is an error when you run mstsc /console, you must
upgrade your termnial server client

to version 5.1



On the server, goto start, then administrative tools, and finally
terminal server manager.  This will show you who is logged into
the server.  You can then right click on

a user and select disconnect or reset. 

After you disconnect the other connection, you may close your connection, and log back in.