My PC locks up and shuts down at random and recurring times.
Games where I crash:
Portal 2: Random times
Shattered horizon: Menu and after 10-30 minutes of gameplay
Crysis: Never
Bad Company 2: It used to be every game. Now it's rare.
Battlefield 3 (beta): Deploy screen. Randomly (Anywhere from 5 minutes in to 3 hours)
Fallout 3: Instantly after loading a game or a few hours after I'm in.
Metro 2033: Never. Yet.
Grand Theft Auto IV: Randomly. Sometimes Menu.
Arkham Asylum: Once after 5 minutes of playing. Never since.
When these games crash, it seems like it always runs a 50/50 chance of shutting down or just freezing. Also, I can usually hear something clicking in the computer before it happens, but as dumb as this sounds, I can never find out exactly what or where it is.
Specs:
i5 2500K @ 3.3GHz (stock) with Cooler Master Hyper 212+ heatsink (One fan).
MSI GTX 560 TI Twin Frozr II 2GB OC (At stock "overclocked" speeds.
MSI H61m-P23 Motherboard
4GB (One stick) Corsair XMS3 1333MHz RAM
Seagate 5900 RPM 1TB HDD.
Eagle Voltas 550W PSU
I'm running the latest Nvidia 285.38 (BF3) drivers.
Also, my GPU temp never goes above 60 and my CPU temp never goes about 52. Ever.