zach, to point out. Shutdowns while playing games: A few things to check:
1. Update graphics drivers/chipset drivers (windows 7 is more likely just to restart the ui instead of restart, but sometimes invalid calls bluescreen the chip and cause restarts). Verify that its the right drivers as well, some graphics cards work vastly different
2. remove any graphics drivers for cards you no longer have. these can also interfere in weird unexplainable ways
3. I'm assuming monitor is working, cabling is intact, etc...
4. Heat is also an issue, clean dust from machine, graphics card, etc as much as possible, air duster is your friend, don't spray components with ice please
5. Power is the next issue, size of power supply is vital, and I recommend nothing less than a 750 Bronze 80+... some games suck more power out of the graphics card (due to stressing the card) than others and the rails on some power supplies can't handle the spike
6. I saw you had it attached to a surge protector, those are nice, battery backups are better as most power your machine from the battery and charge the battery from the wall, it supplies more consistent power and extends the life of the power supply and other components exponentially.
7. Disable other apps, and disconnect from the web. Run a virus scan, this can also be a culprit
8. Ensure that your windows is up to date, and that there are no new updates that apply to graphics, chipset, directX, .net, or other related devices...
9. Replace graphics card cooler or graphics card, recommend replace power supply at same time.
Just a thought transition.