Hi everyone,
Just wanted to share that I had a similar problem when I first built my PC. i7 3930k and a NVIDIA GTX 670 video card with 32 GB DDR3 1333mhz RAM. The PC would hang randomly after installing Windows 7 PRO 64-bit. I resolved the problem by updating the BIOS. Since then I've done one more BIOS update to 3/5/13 date version. Hope this helps someone with similar problems.
This board has given me quite a few problems. Found this thread because I just tried to update my Ethernet drivers to whatever newer version available, and it resulted in internet loss every couple of minutes. Had to restore the system back to previous version. One of my RAM sticks also randomly stops being recognized. I'm an NVIDIA supporter, but this motherboard seems to be a dud.