I had an Optiplex 330 that logged this error message under the “System” Event log.  When you tried to connect to it via remote desktop, it would attempt to connect for about a half second and then the “connect” botton would be available again.

The fix?  Going here:  Display Properties –> Settings –> Advanced –> Troubleshoot, and turning off “Hardware acceleration”.

Don’t ask me…  Some conflict with rdp.dll and the ATI video driver I suppose.  I am also testing updating the video card driver as well.