All those "solutions" with NHancer and Negative LOD bias don't work for most people, they only help some.
However I've found a web page that has animated flash showing how to reset driver settings for particular game via Riva Tuner, AND IT WORKED! Not only for me, but also for 5 of my clanmates (that means all of them with Nvidia series 7 or 8).
Here is it:
http://www.aaa-squad.com/AAreset/AAreset.html
Hope it helps you as well.