I have messed around with the compatibility options and tried running as an administrator. The most I have gotten from this game on XP SP2 compatibility is getting to the mission briefing, after which the game crashed. Furthermore, when this game actually does run, it is REALLY choppy. What's wrong?

Win 7 64bit
i5 2500k
275 GTX

Is there no one who knows what could be the issue?

I changed the graphics options from the folder in the start menu. Things seem to be OK.