Something else I failed to mention:
It reboots when I start a game, it happens just after logging into Wildstar (beta) and World of Tanks.
Its only just started to misbehave like this in the last 2 weeks.
No errors in the event logs. Just the usual "Computer restarted unexpectedly".
BIOS defaults now reloaded. Will retry.
UPDATE:
Well tried optimised defaults. Rebooted just after logging into World of Tanks.
- Screen goes black, like loss of video signal.
- Seconds after, sound starts to freeze and stutter.
- Seconds after that, the system reboots.
Could this be a GFX card problem, or motherboard?