The text below is copied from our Nvidia Driver Sticky. Give these drivers a try and make sure you have the latest motherboard drivers.
Currently, the best choice for drivers is the 84.21 version.
84.21 – available here
The 84.21's have proven to be extremely stable, and give the best performance of all the 80- and 90-series drivers currently available. If you are having problems with your NVIDIA graphics card(s), the first thing to do is make sure you aren't using a 90-series driver.
One thing to note, however, is that 90-series drivers are required for certain cards, including: 7950GX2, 7950GT, 7600GS AGP, and 7100 GS. For each of these, use the 94.24's. If you have an 8800 card, you must use the 97.XX's, as they are the only versions which support 8800's.
Note on installing drivers
When installing video card drivers, it is very important that you follow the correct procedure, as outlined below. Incorrectly installed drivers will cause just as much trouble as faulty drivers.
1. Uninstall any video drivers you currently have, through Control Panel -> Add/Remove Programs.
2. Restart your system, and boot into VGA Mode (tap F8 while the system is starting, and select VGA Mode from the list).
3. Disable any antivirus programs you have.
4. Install the new drivers.
5. Restart your system again.
While not absolutely necessary, using a program such as Driver Cleaner
when removing the old drivers is also a good idea.