PC freezes/gitters and locked processes

[Link]

My PC has started locking up, the kind of lock up you get just before a blue screen, but then just stopping, the repeating noise you get with a BS is the same, just then stopping.

Its random, it happens with Low quality videos, but plays high fine.

It happens in Low end games, but plays SOME high end one fine.
(Shits up on Bit-Trip-Bear, but plays STALKER just fine)

Also when playing a game, some will crash, and the Process will just sit there, i can't kill the process, and i have to restart the PC to get rid of the process.

This is Windows 7 64

[Roph]

Does the event log show anything? =o