Yes get powerstrip as suggested. Also this repost from an earlier nvidia user may be helpful. He was having trouble with overscan, but the drivers referenced may be just what you need.
Nvidia's new Forceware drivers cured it all. These drivers add Consumer electronic display support for DVI-based digital displays, such as widescreen plasma screens (CEA/EIA-861B) according to Nvidia's website. There's a nifty little program called NVKeystone I think in the download that allows you to adjust the screen size from corner to corner. I have my entire computer screen visible now. http://www.nvidia.com/object/winxp_2k_61.77.html