Sounds like a virus/worm problem...if not, what kind of quality is your PSU? Cheap ones often don't reach their labled output, and can have sketchy consistancy.
I got a very weird problem with my daily use machine...it is shutting itself down every 5 minutes...almost on the dot.
It isn't temps, last shut down was 36C on CPU...very cooled off.
I don't know what is doing it, it's not overclocked, I pulled all things that I wouldn't normally use (like my uneeded 56K modem, cold cathode lights)
Ideas to get it work?
AMD AthlonXP 2600+
DFI LanParty KT400A
ATI Radeon 9600Pro
1.5GB DDR RAM
SB Audigy 2 ZS Plat. (w/front drive)
4 case fans
any thing else you want to know?
I am safe from crashes right now...since I am using my other computer (not a system I like BTW)