I have a new flat panel 21

It sounds like you have the resolution set wrong. Typical monitors are setup with a 4:3 aspect ratio. With the widescreen monitors, you have to get a resolution that will support the 16:9 I purchased a dell monitor a while back that was the same way, and I just went in and made sure I had it set for the 16:9 aspect ratio.

Right click on the desktop, go to Personalize(Vista) or Options, and then system tab, and slide the bar along the resolution ruler to the correct size. Play with them a little too, to make sure it fits you best. Some of the higher resolutions will show more screen space, but will have smaller text.