So here's what's been happening:
I tried to load Skyrim in windowed mode a single time, found it really irritating, and switched my setting back to full screen. However, when I try to play Skyrim now, what happens is a sort of fullscreen-windowed-mode hybrid. Essentially, Skyrim launches in fullscreen, except with a large black bar at the top and bottom of the screen. This bar accounts for about 30% of the entire screen, and produces a bit of a visual squashed effect on the game. This is an intolerable way to play Skyrim, and as I have no idea how to fix it. I'm pretty much totally unable to play the game for the moment, without being entirely unhappy, anyway. A swift reply with a solution to this issue would be very much appreciated.