So the game is super choppy for me. When I changed the graphic settings to 3D + Hal which helped, but it is still super choppy when I face the big house.

When I try to run the game in compatibility mode this message appears

A game critical file (win_init.dat) is missing. You need to reinstall the game.

Needless to say, I have tried that and I can't seem to get it to work. Any suggestions?

Nevermind I reinstalled the drivers and put it to 3D + Hal

how do you reinstall the drivers?

http://www.nvidia.com/page/home.html