Specs as follows:
i5-2500k oc'd at 4.5GHz, 1.32 VCORE, 101MHz bclk (Prime95 for 4 hours and IBT Very High for 7 passes: 71c)
ASUS HD6770 GPU
Kingston HyperX 16GB 1600Mhz with Intel XMP enabled
Cooled with Hyper 212 Evo, 3 fan system
Gigabyte Z68-AP-D3 Rev 1 Mobo
OCZ 550w PSU
So I'm getting restarts in certain games, I can play Fallout:New Vegas for hours perfectly but whenever I launch Just Cause 2, Skyrim or Dead Island for 5mins-2hours I get a restart with no BSOD. I have monitored temps and they are all perfectly safe, my GPU is maxed at 52c and CPU 49c. I have tested my RAM with Windows, monitored PSU voltages and went default with no overclock.
I am truly stumped..