go to
www.nvidia.com and look to download drivers, should be on the top bar of the browser. Download the newest detonator drivers, or older version depending on how you feel about graphics drivers. Since it is a GeForce it is supported by Nvidia's current driver scheme.
Once you have it loaded and reboot, if you right click on your desktop and then go to properties, and then navigate to settings tab there should be an advanced button that lets you stretch and make the screen fit.
I am not sure exactly where it is located, but you should be able to find it, just grab the newest Nvidia Detonator drivers.