I have a Windows XP computer that everytime it gets to the desktop it restarts. I do not know the history of the problem other than it is now restarting at the desktop. Does anyone have any ideas what it could be?
Boot into Safe Mode by pressing F8 during the system start up. That should allow you to get into Windows. From there, check your Event Viewer for error messages. Have you installed anything on the PC recently, like a video card or RAM? It could be that. When you're in safe mode, run a full anti-virus and anti-spyware scan if you can.
Hit F8 when your machine is booting and select "Last Known Good Configuration (your most recent settings that worked)" to see if this deals with the problem.
Otherwise you could try checking for errors on the hdd by following this solution:
This topic area includes legacy versions of Windows prior to Windows 2000: Windows 3/3.1, Windows 95 and Windows 98, plus any other Windows-related versions including Windows Mobile.