Random unrepeatable resets from WinXP

Just a few days ago, I was using MSN messenger, and I hit enter to send a message, and my computer when black, and started to boot up again. It didn't happen again until today, a few minutes ago, when I was playing an MMO, and clicked on something, and it reset.
Is there any way to fix this problem? I had it before I rebuilt my computer, and it only got worse with time. Sometimes it goes for a week without resetting, and sometimes it does it twice in a day.

Any help at all will be greatly appreciated,
Spartan

 

it could be a device driver that's either not installed properly, or is the wrong driver for any of your hardware, make sure that you have all the correct and up-to-date drivers.

it could also be a psu problem, maybe you could try a friend's psu and see if the problem persists?

 

I'm fairly sure it's not the PSU, because I've changed it and it's still reset on occasion. I don't know how I could have gotten any incorrect drivers, but how would I check? Device manager?
Also, do you think it could be SP2 that did it?

 

By default XP is set to reboot on errors.

Right-click My Computer, Properties, Advanced, StartUp and Recovery, Settings, and uncheck Automatically Restart.

If that fails, make sure that all your hardware is compatible and that your drivers are up to date.

 

That sounds like that might do it, and if so, I thank you very much! If not, I'll post again, thx for the help!

 

Spartan, that only lets us diagnose the error, not fix the problem.

When/if you get an error please post exactly what it says and any filenames mentioned.