It could be the setting on your video card making it do exact pixel by pixel no expanding, or the monitor. My monitor can do stretched (looks like shit for morons), Aspect (keeps same proportions but blows up to max height), or Real (that's the pixel to pixel one).
Video cards have stupid names for whatever. Like ATI "centered" etc or this or that. half of it is broke anyways and the rest is labled wrong. I am doubting it's the game. However, on that topic, you need to use High Resolution patch and jump over those hurdles. Windows 7 doesnt run it right at all, but it doesnt have a problem with sizing it however.
