So yeah, it arrived today along with a new motherboard and RAM. Me and my brother spent hours trying to install it (had to replace the motherboard, switch the CPU, Windows had to reinstall all drivers etc.) and everything seems to be fine so far. Hopefully I won't run into problems anymore, at least for a while 
Here's a picture of it:
Geforce GTX 260. Seems to be a good card, and from my tests I can run games with considerably better settings than before with higher framerates. Yay!
Also I can finally play Risen (also pictured), which I bought over a week ago. So... seeya, I'm off to do some gaming!