What system do you have? I think that pressing Fn+F7 on _older_ inspirons will help. On the newer models (8500 and up, 5100 and up) you'll have to check the video options.

First of all, what system do you have?

Hey, thanks for the suggestion, HMKrieps.  I had been pulling my hair out for 6 hours attempting to increase the screen size on my Exasperon 8000.  Unfortunately, Dell has deleted all the user manuals from their data base, so I couldn't figure out what all the little symbols meant on the key board.  Your idea to hold Fn and F7 was perfect.  Thanks again.

Fn+F7 usually fixes that problem but sometimes it doesnt. If ever that happens, you would have the aspect ratio depending on what video card you have. For some systems, like the 1100, there's an issue wherein you're unable to remove the black border if the resolution was set to 800x600 and below.

I have an Inspiron 1100 which I bought 2 months ago.  I tried fn+f7 and various other things.  I'm running windows XP.  Thanks all to everyone who replied above.