Fixing a HUGE screen size

This is most embarassing, but, while scanning the size options in the display settings on a Windows 2000 Pro machine, I slipped and selected an absolutely huge setting. Its so big that I can't maneuver the cursor to the button to resize it. I havenever run into something like this before and I'm stumped. Is there a way to hack it back into size thru the registry, or does someone know a simple trick to fix this goof up?

Thanks

Mike