I recently built a new computer specifically for gaming (specs posted below) but it freezes completely while I play any game (Specifically Skyrim or Borderlands 2), requiring a system restart by holding the power button. I've tried everything I can think of. All my drivers are up to date, I've tweaked graphics settings both basic and advanced (such as setting the affinity of the games to just 2 cores, as I have seen suggested online, as well as adjusting the 3D settings in the NVIDIA control panel). I've run memtest86 and the memtest that is on the Windows 7 disc. Reformatted and reinstalled fresh Win 7. System temps are well within limits. There are other things I've tried that I can't think of at the moment, but I've spent a week troubleshooting this problem with zero luck.
Both memtests came back clean, by the way. 0 errors.
If anyone can help me solve this, I would be so grateful!
Operating System: Windows 7 Home Premium 64 bit Service Pack 1
Motherboard: Gigabyte GA-990FXA-UD3 Revision 1.1 with BIOS version F8
CPU: AMD FX-8150 3.6GHz Eight Cores
Ram: Corsair DDR3 1600MHz 4x4Gb
GPU: ASUS GeForce GTX 660
HDD 1: Hitachi 300GB in 2 partitions, Windows on C:
HDD 2: Seagate 2TB
PSU: SilverStone 700W