This may not really be necessary, but here's how to do it anyway:
- Download and install Driver Fusion (it's free)
- Uninstall the NVIDIA Graphics Driver using the Programs and Features control panel
- Reboot into Safe Mode. To do this, choose Restart, and then be sure to be holding down F8 when you know Windows is about to start, and don't let go until you see something change on your monitor.
- Choose Safe Mode
- While in Safe Mode, open Driver Fusion
- Click NVIDIA Dispplay
- Click Delete
- I can't remember what happens next, but follow through with this and then close Driver Fusion
- Reboot and allow Windows to start normally
- Install the new driver
Of course, you will also want to make sure that you have the installer. So, if you don't have it, then download it from NVIDIA's website: Drivers | GeForce
That way, you'll be ready to run this installer when you're done with the steps above. However again, I don't know if this is really necessary.
Now before you do this, I'm curious: why do you want to do this? What's happening?