I-War2 Won't Run on Vista - Help!

I recently got a new computer (my last one died), and I-War2 won't run on the Vista operating system. It keeps saying that it can not find a suitable driver (I have an NVidia 8500 GT). Has anyone been able to fix this?
I read another post from someone who was having the same problem, but updating the system didn't seem to help.
Any advice would be much appreciated.

Problem has been fixed, thanks.