By coincidence, I have just posted this on Brink's 7 site. Possibly will solve the same problem with Vista?
Fwiw::
I do not know the mechanics of Video drivers, but my own experience with one of my laptops might help others with older cards. (Go 7600 in my case)
The built in "7" driver worked fine for me, except for a couple of sites (maybe there were many others) where I got a strange, and unreadable, kind of "quad" effect, There were four, poorly rendered, pictures where there should have been the one. With a lot of tests, it did seem to be some conflict with Java.
I tried different drivers, past and present, even third party. I was on the point of temporarily giving up on "7".
So then I reinstalled, accepting Microsoft's drivers. I downloaded and expanded the latest drivers to a designated folder.
Back into the device management and selected "update drivers". I pointed the panel at my new folder and "7" got excited and installed the drivers. I now have a machine working perfectly, whatever I throw at it! Why it would not work with a normal Nvidia install, I have no idea