I have a system that has windows XP pro loaded and when the user logs in the syetem will restart. I brought the system to lab to work on it. Booted it boots fine and just left it to sit and then it rebooted on its own.
Got the system into safe mode and it works in safe mode not well but well enough for me to uncheck the reboot option so I could see if there was an error.
Sure enough "page fault in non paged area." Pulled the minidup and looked at it. It indicates the driver CLASSPNP.SYS caused / causing the crash.
I checked the memory and it checks good
I substuted an old backup copy off the system while in safe mode that did not work.