Drivers for that video card should come in-box. You SHLOULD have everything you need to maximize the potential of your video card at max rez and fps. If your looking to get the tools that come with the card, they should be available at the Nvidia site, just download the latest Vista ones, as the platforms are very simliar, you should get the same results.
I really would let Windows 7 do it's own graphics management, that's what it's designed to do.
as for your router, try taking off the password from the router completely, by unplugging and resetting it. See if Windows 7 will connect that way. It's seeing and communicating with the router, that's a bonus; now you just have to get through it to the net!
Let us know what the above does for you, and if your actually getting side effects from not having third party
driver-based video
-D