NVIDIA still haven't fixed the crashing and hanging problem. After fault finding for a few days and even buying a new video card (Gigabyte GTX 650), I just found out that it was the latest NVIDIA drivers causing my hangs and restart issues. I went back to NVIDIA GeForce v314.22 (25-03-2013) WHQL, and all is fine now. Thanks a lot NVIDIA. :bang: PS: I also tried NVIDIA GeForce v326.41 (30-07-2013) Beta and it also has the same problem.