go to desktop, right click, go to properties, then go to settings, then advanced, then click the tab for your video card, see if you can make the adjustments you need there, and don't forget to set the refresh rate as high as you can, and keep the box checked that says hide modes that this monitor cannot display. I just setup my new 50" Samsung DLP for use as a dual monitor and had to use the DVI output with a DVI-VGA adapter and using the PC input on the tv. I was able to set the resolution of the tv to it's native resolution and it looks fantastic.