Computer restarting out of nowhere (Diagnosed it, don't know what to do)

I'm sorry, I seem to have posted this in the wrong area... Is there anywhere on this forum that relates to desktops?

It all started with playing games. Browsing and using the computer normally would be just fine. Playing Assassin's Creed and I would crash about 2 minutes into the game play. Less resource intensive games like Fallout would take about 20 or 30 minutes to crash.

I ran Memtest and passed. I've turned to using OCCT to benchmark this computer. 1 hour of CPU, doing fine, 1 hour of GPU, doing fine, and I test my Power Supply and crash at 16 seconds. Could someone help on what to do? Perhaps there's a log I could provide that will give more detail?

My apologies, my first build, and it's been a year and a few months since I've made this computer, so I guess I'm bound to run into problem now.

Specs:

Intel Core i5-2500K OCed to 4.5
8gig Vengeance RAM 1600
MSI AMD 6950 2gb unlocked and OCed

And what I think the problem is?

Rosewill BRONZE Series RBR1000-M
Newegg.com - Rosewill BRONZE Series RBR1000-M 1000W Continuous@40°C, 80Plus Bronze Certified,Modular Cable Design,ATX12V v2.3/ EPS12V,SLI Ready,CrossFire Ready,Active PFC"Compatible with Core i7, i5" Power Supply
.

 

If it's still under warranty, you can call Rosewill/Newegg for a replacement. Otherwise, sounds like you just need to get a new power supply.