Maybe I said it wrong. Everything on my computer works fine but I can;t move things around on my desktop( dragging files or pics to trash or to iphoto etc...)Set Expose to start your screen saver by swiping to one corner. Then require your password to wake from your screen saver.
dock works fine,when trying to move or delete anything on my desktop the computer tells me to enter my password and then says" operation could not be completed because you don't have sufficient privileges for some of the items."Maybe someone played a prank on you and took a picture of your previous desktop and then set that picture as the background image while turning off viewing of hard drives in the Finder's preferences, and also auto hiding the dock?
It's a stretch, but we might as well establish that first.
Does this problem happen in a normal Finder window, or just on the desktop? Or is the dock at bottom of the screen locked?