That depends on the display. Some of them, you need to either activate a PC or computer mode, or you may need to disable overscanning, or LCD overdrive. You can usually fix this on the computer itself, if you go into the display settings in either the NVIDIA control panel or the AMD Catalyst Control Center, depending on who makes your video card. If it's AMD, you can just right-click your background/wallpaper, click Catalyst Control Center, then click the My Digital Flat Panels category on the left, then click Scaling Options, and you can mess with the underscan/overscan settings to scale the picture in and out on the display.
I don't know the NVIDIA version offhand, but it's going to be a similar set of steps. If you have an Intel or other manufacturer for the video card, then I don't know, you'll have to Google it; but it's usually fixed via underscan or overscan settings.
"VICTORYYYYYYY!" -Johnny Drama