Intermittant PC restart.

[gillenr]

About once a week, my PC restarts for no obvious reason. I'm on WXP SP2 & only OE & IE are open.
Is there a log I can go to to find out what is causing this?
Thanks.
P.S. I was watching it once, & it just did it - no msgs on shut down or start-up.

[Tom]

Overheating?

Remove the top and examine for dust build up.
Do you have a cat?
Smoke? (YOU, not the cat!)

Can build up and clog the fan.

Does it happen after you have been on for a while?

[gillenr]

Not much dust, do smoke, no cat, always about 6+ hours.

[Tom]

Could still be overheating, if time seems to by correlated to shut downs.

[gillenr]

It appears to be caused by my UPS - it isn't showing a fail light, but the battery appears shot, & I'm dropping out on the weekly auto self-test. If it is the battery, I won't respond further.