My HP slimline s7700n video card is not working after installing XP?

I recently uninstalled Vista and reinstalled XP Home on my HP slimline s7700n and now I can not play my games. It says that it failed to find any DirectX 9.0c compatible graphics adapters in the system. I know that it worked before, what do I need to do?|||Go to the HP website and download the XP video driver for your model of computer. It is different to the one that Vista uses.