Don't use the self-extractor. Extract the driver files into a new, empty folder.
Uninstall all current drivers. Load the standard VGA. Then use the Add/Remove applet in the Control Panel to manually browse to the folder with the drivers, and choose your model of video card from the list.
If no list appears that contains your card (or no cards at all), or if there is an error in the Device Manager ... "upgrade" the VGA drivers in the Device Manager, again by browsing to the folder that contains the driver files.
You can extract the files by right-clicking and dragging the driver installation .exe file to the empty folder, and then choosing to extract the compressed files from the right-click menu.
The self-extractor that comes with the latest nVidia drivers is often corrupt. Be sure that you did not use a Download Manager to download the driver.
This is well-documented problem with the 21.81 and 21.83 drivers.
If you haven't already done it, this might also be a good time to upgrade to DirectX 8.1. The final version is out. Do this before upgrading the nVidia drivers.
If necessary, in order to completely remove all instances of the Detonator drivers from your system, download and run Detonator Destroyer, after using Add/Remove Programs to uninstall the drivers.
(A lot of people are claiming to have good results with the 22.80's, FYI.)
If none of this works, check for driver conflicts, such as with the sound card. It's possible that you might need to uninstall/reinstall the sound card, or another device before adding the new card. That might include choosing another PCI slot for the conflicting device.