Hmmm, that's another possibility. Thanks.

Still a bit strange that when booting it sometimes doesn't find my hard disk, or does that make sense when there's a power shortage? I guess it's possible, Windows tends to go haywire when it needs to boot a little bit too often.

I will do a Google search, but do you happen to know of a tool that's able to measure the output of my power supply or somehow check if it's still alright?

My graphics card is secured, rock solid with several screws, it's going nowhere. It looks rather clean as well, no excessive dust bowls in the fan or things like that either. Overall my PC is quite dusty, but I did clean it up a bit with a vacuum cleaner now.

The main problem is still the same though, it will crash while trying to perform the more demanding tasks, like playing 3D games.

My power supply is a 750Watt by the way, worked fine for many months. It could of course be worn down now or even broken. As I type this, my PC has only crashed once today.