Ok first off you have to try to install the driver. It will extract all the files and attempt install and fail saying you don't have the right video card. After that open the nv4_disp file in the 177.41 folder and in an old whql folder for your video card. Then go to the bottom of your original drivers _disp file and copy the highlighted line and paste it into the 177.41 nv4_disp. This tells you the number for the part near the top you need to copy paste.Then go to the top, copy the highlighted part for your card and paste it in the same section for the 177.41 nv4_disp. Then save and run the setup from the 177.41 folder. After that just download the physx driver off the nvidia site and install it. Then run Nvidia physx properties and click on the settings tab, geforce physx will have a dot on it if its working. Hopefully that helps you and I hope it works for ya.
Edit: Btw the point of going to the bottom first is because you can just look for your card 8800gtx on the right hand side. The part to the left of it "NVIDIA_G80.DEV_0191.1" is what you look for near the top of the file to copy + paste over for your card.Edited by Azazel - 6/27/08 at 7:36pm