I guess you have tried reinstalling already? If not, then try that, would be easiest.
Maybe something was for some reason not copied when you installed the game.
Also, some games require software like Direct X or the C++ Redist and actually have it on the medium they’re on but don´t install the additional software automatically.(Happened to me sometimes, though never with Steam I think)
If you have the game on DVD then try looking for additional software there. It´s often in a certain folder which is named in a plausible way(forgot what it exactly was) so you shouldn´t have problems finding it. Even if the game did install everything, you could try installing the required additional software again. Maybe there went something wrong when you installed it the first time.
Maybe the game also requires software it doesn´t provide. You surely can find a list of software requirements online.
Do other games run as they should with your GFX-Card? If yes then I guess there is really just something missing in your game files or software the game is using. If not then you got a hardware problem.(At least most likely)
This is not very technical help. Maybe it actually does help anyway. If no one else here is able to help you then you should go to the official forums and open a topic there or actually use the support.
Now that I come to think of it, could it have something to do with PhysX maybe?(Does the game even support PhysX?)
Anyway, good luck