I was playing Shadow Warrior 2013 (the "classic edition, not the DX11) and my PC totally freezed. I though it was nothing but just a moment ago it happened again. It seems to happen after a long play time but I can't really tell. No error messages in the windows event logs, and my PC isn't overheating. These crashes are 100% related to something with the game.

Any idea?

Are you using the latest amd/nvidia drivers?

Yes, my drivers are up-to-date. (Sorry for the late reply)

lol shouldnt be a problem with latest version of your video card that is just plain stupid...