I have a Laptop running Windows XP and all the ICONS on my desktop have rotated 90 degrees and everything that comes up is rotated 90 degrees. What did I do and how do I undo it?
If you have nVidia graphics then there is an option in the nVidia control panel for rotating the display. I suspect that you may have inadvertantly activated a shortcut for that function. Just go into the nVidia control panel and rotate it 'til it's correct again. You should be able to access the nVidia control panel by right-clicking on the desktop.
If you have other graphics, then I suspect that it is a similar problem but I'm no longer very familiar with Intel or ATI graphics drivers so can't really help further.