give this a try.
Always create a system restore point first.
1) Download driver cleaner
http://www.driverheaven.net/cleaner/ then install.
2) Open driver cleaner then find the option "cab cleaner" then use. This removes the old 27.42 drivers from sp1. (if ati cards skip to option 3)
3) Remove control panel first don’t reboot, then drivers from add/remove option.
4) when asked to restart do so but when restart hold f8 then select "safe mode" from options given.
5) When in safe mode open driver cleaner for a second time then select "NVIDIA” then press clean. This removes any INF files windows leaves behind.
6) When complete reboot to normal, if cab cleaner is successful you should get the add hardware window instead of installing above drivers (27.42).
7) Cancel add driver window unless it’s an unzipped & locate file type driver. If its .exe type goes to #8
7a) disable any anti virus software. (Only do so when offline)
8) Locate & install NVIDIA or ati drivers.
Reboot and things should be fine.
Ps after option 5 you might be worth reinstalling dx9.0b and the latest chipset drivers for your mobo.
i get 17k on 3d2k1.im sure your probably aware of this but what psu do you have?