I don't know what happened. when I log in the desktop is black and I cant see any fonts. I can see the icons but everything else is black so I cant see where to click. Is there a way to fix this if I log on as a different user with administrative rights?
Right click anywhere on the screen and with luck you'll hit a blank bit. Press the Alt key and R together to give you the Properties form and that will show up with the Desktop tab. Click on that and select one of the built-in wallpapers then click Apply and OK. That should revert your screen to something readable and you can choose your own wallpapers when you've sorted out the font problem.