I have just lent on my keyboard accidently and my whole screen has move 90 degrees? not just the toolbar but all icons and windows, even the mouse when moved right the cursor moves up the screen. Its a tough picture to imagine so look at it like this "To make this right i would have to turn my "whole monitor" onto its side for it to be ok"
Have looked at the settings but can't find anything any ideas??
Some LCD monitors have the ability for the screen to be rotated 90 degrees, presumably because this is better for working on tall narrow documents. I think you have accidentally found the shortcut for this.
I have a new computer which has a small red icon labelled ATI,in white,in the system tray.This has the ability to allow me to rotate my screen and reduce or increase the display resolution.Maybe you have it as well.