First off, I'm plugged into a battery backup power supply. (I don't know if that's related or not.)

Also, I think my Windows Update may have something to do with it as well. The last couple times it's happened the yellow Windows Update icon popped up in my taskbar. I put off downloading the update because I didn't want to restart my PC. I woke up this morning and my PC was restarted without me doing so.

I seriously doubt it's a heat problem. My temps are moderate.

Is it possible that it's actually something that I can change by going into my Control panel and changing settings?

It could be blue screening and you have XP set to reboot after a blue screen. Check the System Event Log for messages. A flaky power supply could also cause this symptom by switching off and right back on. The battery backup would not prevent this from happening.

This post has been edited by 98springer: Feb 14 2008, 01:24 PM

Something else you can do to see if your computer is bluescreening is th turn off auto reboot. One problem with windows update is that the computer will reboot after installing any updates. I want to read up on any updates before i install them as many do not apply to my computers and are unnecessary.

Open System Properties via Start > Control Panel > Performance and Maintenance > System
( System Properties may also be opened using the WinKey+Pause key combination).
Select the Advanced tab and then click Settings in the Startup and Recovery section.
In System Failure section, clear the checkbox next to Automatically Restart.
Click OK and OK to exit.

Every computer i have running is always plugged into UPS's and i have had no problems using them.

You can also disable windows update( i always do)and then manually download any updates you want.

http://www.theeldergeek.com/disable_automatic_update.htm

SRX660