Cameltoe...If you havn't fixed your glitch yet...I do believe that it sounds like you just dloaded drivers that don't work right.It happens...I have A GF3 and I can jam all the way on all vid settings.If you havn't found a chioce of drivers yet,go here...
http://www.guru3d.com ...they have a huge selection of drivers for all video cards.New drivers will probably fix your problen,seeing as the fact that it worked fine before!!Just keep changing them till you find the ones that work.I would start with the newest and work down.No need to use real old and maybe outdated drivers.