There could be a problem with the driver
you are installing - or your video card just doesn't like it. You can try installing a previous version (older version) driver to test.
Or your video card may have gone south (died - the slow death). If it works when using the generic drivers
that load from Windows but then fails when you load the nVidia drivers it means that the advanced features of the card - like 3d graphics - are failing or have failed.
You can play with the settings for the card in the nVidia Control panel to see if you can get it to work with the driver, or at the very least isolate wherein the problem lies. If you have played with these settings in the past you should try resetting the factory defaults.
Also try re-seating the card, and check that all the contacts are clean and there is no dust in the slot. Re-check the power cord(s) to the card too.