Although I'm not sure what specifically is causing the problem, I can surmise that you're experiencing a 'feature' in Windows 2000/XP. By default in these OS's, if there is a major system crash the computer will automatically reboot. You can change this by right clicking My Computer->properties->advanced->start up and recovery and uncheck the 'Automatically Reboot' box.
Now when your system crashes you will likely see a classic Blue Screen of Death.
