Hello, my friend has windows 7 on his computer. The other day when he turned it on, he said he had a black screen, no wallpaper, and all his taskbar icons were gone. and his documents were erased. Then when he tryed to change the background it wouldnt change, just stayed black, but all the program files were still on the account under program files. The pictures were gone, and on his other account nothing was changed. What could this be from? and why wont it let him change his background?