Computer Keeps restarting when under heavy load!

Try clearing the CMOS. What PSU do you have? Have you tried a different PSU.

I have a corsair power supply, 620 watts heavy duty. But I think I found out the problem. I upped the cpu voltage and it seems to be alot more stable. It hasn't restarted at all. Even after a 3D mark stress cpu test

Sometimes it's that wasy  

lol computers are confusing!!!!   wat r u running?

Currently running a 939 X2 4200 with a 7600GT video card, 2GB of RAM and 3 SATA hdd, a 160 for OS/programs, a 250 for photos and music, and 320 for video. Don't game so heavy use is video editing. Want to replace it when the quad core comes down in price and can see what AMD will offer. Also have two AM2 X2 3800 with onboard video, 2GB of RAM, and 2 hdd in each, one each for back up. These are the machines my wife and I use for work. These should last for years but won't because a few months after I get the quad I'll get the urge to build something else and one of my grandkids will need a new machine, always pass the old ones down. My wife is OK with building a new machine as long as I tell her it's for the kids.  

hahaha! Well its for the kids right?  
Your systems sound complicated:S I just bought the 3800+ because I love buying cheap things and overclocking them to match an expensive cpu. But so far the 3800+ AM2 seems to be a poor overclocker:| My next cpu is the 6400 X2 because I bought it really cheap I'm waiting for it to ship in 

I just hope its not a disappointement 

I really don't overclock but from what I've read, Intel is much better for overclocking but that would mean buying a new mobo.

Yup not doing that again, Plus I've always been an AMD fan so I'll stick to AMD for now