A family member is using a 2.1GHz Intel Celeron based system that I build about 3 years ago. It's only used for surfing the web and Word, so is adequate.
After being powered up in XP for an hour or so the screen goes blank and the system is unresponsive.
What I've done:
-When it is booted with a Linux Live CD it stays on, and working, so I think it must be an OS (XP) problem.
-The System Log under Administrative Tools has no errors
-Under "Power Options" everything is left on