lcd cropping software? Answered

I just built a DIY projector for my room (basically an overhead with an lcd and fans slapped on). Many people that do this use a 15 inch screen, but my family recently burnt out the backlight of a 17", so I used that. Anyways, since the stage of the overheadprojector can't see the whole LCD, some parts of the image get cut off. Is there some sort of software to essentially shrink a screen so that I can get the whole image viewable to the projector?