<hr>I'll throw this into the ring: Has anyone any other candidate for the cause other than overheating? <hr>Well, I don't know about that, but I agree with Bob that we shouldn't mess around with glibness when a poster is trying to solve a serious problem.
The question I would ask him to check is the machine's BIOS and WinXP for power management. It is possible that the BIOS and WinXP are "fighting" over managing the power of the machine. This was a real problem for me with a few older Gateway laptops. If there is anything in the BIOS about power management, I would turn it OFF and let Windows manage the power of the machine.