Monitor screen shifted up

When I turned on my computer, I noticed as soon as I was on my desktop that my screen has shifted up about 1cm. I went to the Screen Resolution, but it's already configured to the correct settings. I then tried to restart my computer, and that didn't work either. So, lastly, I tried to unplug my monitor, waited about 5 seconds, and then replugged it. That didn't work either. I'm not sure how to fix this. Any ideas? Thanks