The other day I was working on a Windows 2003 SP2 server that was no longer displaying anything other than the Windows desktop. I could not bring up the start menu or even see the bottom menu bar. This naturally was a problem because I wanted to set up a new Web site on the server.
In my experience this problem with Windows is most likely caused by Windows running for too long without a restart, so the standard fix is typically to restart the entire computer.
However, restarting the server was not an option since at that time it was being actively used by other developers for development and testing. So rather than cause trouble for everyone, I decided to look into setting up desktop shortcuts to the programs I wanted to work with.