Xbox screen suddenly magnified, won't fit all of picture on the screen?

I was downloading a demo on my xbox 360 and all of a sudden, the aspect on my screen changed to where not all of the picture would fit on it, like it was magnified. I can't figure out what happened or how to get it back. Is there a way to change the aspect ratio on your xbox 360? Help! I don't have the red ring of death either, so i'm stumped.Xbox screen suddenly magnified, won't fit all of picture on the screen?Also check your tv settings the full screen/widescreen/wide zoom etc. may have gotten changed.Xbox screen suddenly magnified, won't fit all of picture on the screen?go to your dashboard the 4th blade, go over to display settings and change it there.