Computer Forces Shut Down Randomly?

[Jasio-]

Windows XP
Athlon 64 processor
1gig ram
200GB harddrive
128 GeForce 6600
Current Core Temperature - 46C

Computer just instantly shuts off at a random time.. it turns on normally.. stays on.. if its any revolation, the 2 times it crashed i had a lot of stuff open.. but i mean seriously for what im running that cant possibly crash it..

Anyone had this happen.. how did you fix it. Virus, i dont think so.. AntiVir and McAfee both updated, SpyBot and Adaware also being used..

Edit- If i can read correctly.. im using a 500WT power supply..

Thank you for your help,
Jasio

 

[MistaRip]

it just shuts off? doesn't freeze?


sounds like your processor is getting too hot.. is the fan spinning on it? r u overclocking?

 

[Jasio-]

it just shuts off? doesn't freeze?


sounds like your processor is getting too hot.. is the fan spinning on it? r u overclocking?

Well, im not overclocking, fans spinning. It was fine for about 2 hours or so until just now it happened again, i was running 2 MSN, AIM, AntiVir, McAfee, Diablo II, Diablo II Item Editor, and maybe FireFox

This has also never been a problem.. I've had Yahoo, AIM, 2MSN, Morpheus (music dload program), Windows Media Player, Diablo II, D2 Editor, multiple FireFox, and probably even more.. this started happening today

 

[Jasio-]

Can anyone help?