Please perform the following:
Make sure that VIDEO BIOS shadowing is disabled in your BIOS.
If you have a network card installed, please try changing the connection type from the automatic sensing option, to the type of network that you actually use (10BaseT, full/half duplex etc.)
Make sure your GeForce card is not sharing an IRQ setting with any other hardware device in your system.
Disable auto-mipmapping in the Nvidia control panel. Please be aware this may result in reduced image quality and or performance.