Well, IF the Nvidia GPU is dead...it's dead. If not, and you just want to reinstall the driver....
B]DDU Instructions - Nvidia[/B]
1. Get this program, here:
https://www.wagnardsoft.com/ ...get the latest version, and save it to your desktop.
2. Get your vid card driver here, use the
Manual Search:
http://www.geforce.com/drivers ...save this to your desktop.
3. Run DDU (Display Driver Uninstaller) choose the "Highly Recommend Option", and just do what it tells you. If it wants to go into "Safe Mode", let it.
4. After it's done and comp has rebooted to normal mode, just double click the Nvidia driver to install. If it want's to reboot, let it.