My own rig has recently begun randomly restarting itself, seems always when watching videos (youtube, facebook, etc) the computer is NOT BSODing. I know this for sure. I disabled automatic restart on system failure and there is absolutely nothing logged other than the computer was shut off unexpectedly. Quick specs: i7-3770k (stock, not overclocked) Intel Z77BH55K board 16GB DDR3 1600 RAM GeForce 550 Ti Board Samsung 830 SSD (primary OS) 2 x 500GB Data Drives in RAID-1 Antec 650W PSU Im suspecting the power supply, just because it's the only component that is not new. It's from my last i7 build, but its about 4 years old. That's purely a guess, and I might just replace it and see what happens, unless somebody else has a better idea.