My screen resolution is quite small, but when I try to change it, i can't. but that is only part of the problem I have. there is a part of my screen that shows the top section of the screen on the bottom part of the monitor (as best as I can explain). it's like there is a dual screen within the same monitor. it's just not showing all of the second screen. How do I fix this?

What sort of monitor are you using? On which version of Windows(/etc)?

well, I am using windows xp on a toshiba laptop