Just started happening, when I leave my PC on overnight to download from the Internet in the morning it has turned itself off.I checked Power options in Control panel everything ok there. Alsp when I start it sometimes it will boot up to the XP logo screen the go into shutdown mode and the power up agao=in all on its 'ownio'
I am running XP home edition with SP2 As usual thx in advance
Have you checked the ventilation holes at the back and side of the PC to make sure that they are not blocked up by dust, dust can build up very quickly if you leave it downloading overnight on a regular basis. Dust is the main culprit of the computer overheating, it might pay to check your cooling fans are all working too.