I have a Power Book G4 Laptop Mac OSX, and I seem to have messed up something in my display preferences. While looking to choose an image to put on my desktop I believe I selected a .zip file and it completely froze my system preferences. Now every time I go to "Change Desktop Background" via the desktop it freezes. Not the whole computer thought just that app. Does anyone have any thoughts on work arounds or some way to reset defaults on the desktop ? Its probably easy but I haven't been able to figure this one out.