If you have GA-P43-ES3G revision 1.4
Go to GIGABYTE - Motherboard - Socket 775 - GA-P43-ES3G (rev. 1.4)
and download all drivers that are applicable and newer than you currently have.
You can also get to revision 1.3, 1.2 and 1.1 from this site. You will have to know the revision of your motherboard, which I'm guessing you can discover in your bios, or visually from the motherboard.
Then make sure you have the latest video driver from NVidia: NVIDIA DRIVERS 285.62 WHQL
Finally, go to Intel's site and auto detect for latest updates: Intel® Driver Update Utility
You might also verify you have the latest bios - F14. This may vary is your motherboard revision is older, as discussed above.
Let me know how things are after these changes.