is your video card an "onboard graphics chip" that shares system memory?
If so how much ram is installed on your motherboard? It may be that more ram is required or that if you have onboard graphics they can not handle the game.
you may need a more current version of directx, click start, run type dxdiag and this will tell you what version of directx you have, although I would think this has been updated when you installed the game.
if you are unsure of graphics/ram then click here and download and run aida which will tell you all about your system.