Why did my computer screen change?

Okay, so I was using my computer and talking to my friends and I accidently hit a button combo on the keyboard (I can't remember what I pressed) and it changed my screen to be really big and a little blurry. Why did this happen and how can i change it?Why did my computer screen change?
it was probably a keyboard shortcut to something, possibly something like changing screen resolution.



in windows xp:

try going to control panel (from the start menu or from the ';My Computer'; icon), selecting ';Display'; and the ';Settings'; tab, then changing the screen resolution so that it looks right. (if it changes and looks bad and you can't click ';No'; then don't touch ANYTHING and after a short amount of time it will change back anyway ;D)Why did my computer screen change?
Hit Ctrl = Alt= Delete (at the same time) and reboot.

or try pressing the top left hand corner ESC button.

Try that to fix it.

Let me know if still having problems.

Are you running Windows XP or Vista?

If XP = go to START = Control Panel = Display = Change your screen resolution, it might be to low, like 600x1200. Make it higher. Try that also :)