First off you should update the components used for gaming, so download and install the following:
1- Make sure you download and install the latest software from here:
NVIDIA Graphics
2- Install these updates:
DirectX (You need this whether you running DirectX 9, 10 or 10.1)
C ++ for Vista 32 bit
Once you've installed the above reboot your pc. Once your back at the desktop download this:
Utilities.zip It contains three shortcuts, when you run the defrag shortcuts it open a cmd window. That window will close by itself when it is finished so be patient. Once the last shortcut has completed reboot your pc again and then try playing your game.