I believe you are looking for adjustments on the monitor itself (adjustments for horizontal and vertical size). Most monitors have an auto adjustment function as well. You'll have to refer to the owner's manual for the specifics on your monitor.
I changed the resolution of my monitor, then changed it back and now I can't seem to get things to fit all the way on my screen. My desktop is running off the edges and windows are slightly too big. I tried restoring defaults and this didn't help. Any help would be great. Thanks,Chip