NVIDIA's great. It's a company which makes Graphics Cards for Computers, basically the hardware which powers the visuals.
There could be many issues why this is occuring. Has the problem ever occured in the past? It could be anything from RAM, BIOS, Motherboard, Monitor or Windows Driver Issues. Essentially these are all components in your computer which could be attributed to the problems that you're experiencing. I won't explain them to you since it will seem insignificant.
I'd like to you do the following, this will make the process a lot easier and give us a fundamental understanding of your computer.
1. Click Start
2. Click Run
3. Type in the Run Dialogue box, 'dxdiag'
4. Click the Graphics/Video Tab once the appropriate information has all loaded.
5. Please tell us what Graphics Card you have, It'll list the appropriate information under 'Vendor' and 'Make'. I'm assuming it will be an Intel Onboard graphics card, but just in case.
Please follow this information then I'll do my best to help you.
I'm saying this all off the top of my head during a study period so I hope that the procedure I've given you is correct, although I'm quite confident that it is.. hehehe..