PC randomly reboots - NOT from sobig virus-could it be power supply?

[luvbouvs]

Hi all,
P3 Win98 SE PC with 128M ram has a burner, palm cradle, and scanner attached. I have run virus scanners, trend micro virus cleaner (even though none found), run the system file checker (nothing corrupt or missing), and regedit (again, fine). The system is 3 years old and I am thinking the power supply is going. Before I bother going through the hassle of replacing it, any other thoughts would be greatly appreciated.
Thanks!
Michele

 

[Rob2806]

Have you checked the cooling fans? If they are on their way out, it could lead to these problems.

I recently replaced the one on the processor. It appeared to be working but on closer inspection, it was turning quite slow. They should rotate at high speed.

Also have you run Spybot & Ad-Aware to make sure nothing is going on in the background.