From the look of the thread title, you sound angry. HOW DARE YOU BLAME NVIDIA!
(joking)
Anyway, the problem IS from your driver folder/s.
SO, this is my proposed solution:
DOWNLOAD, BUT DONT INSTALL (Hopefully you know the difference)
NVIDIA DRIVERS 306.23WHQL then, go to safe mode.
Select your start icon, and type "Device Manager" (without the quotations).
Expand the Display Adapters tab, and right-click your graphics card (in this case, Geforce 8400GS). Uninstall it, and delete the driver software too.
Reboot your computer, and wait for ~5 minutes for your computer to recognize the card again.
Reboot your computer ONCE MORE, and INSTALL the new driver.
It should work (that process^^^ above is a safe install), post back later if you want...