sry about originally posting in the wrong place. still have the problem that the wallpaper is changed to just plain grey instead of my actual picture. well its changed to mybackground colour instead of wallpaper in the display options menu of windows. on my friends laptop nothin happened and her background stayed the sme as before i put in the usb, until i removed the usb safely etc, her background changed to grey also without the usb in until the computer weas restarted. it does not work at all on the university computers.
the picture is in the corect folder and called the correct thing. not sure what true bmp means but i guess its a picture which started life as a bmp and i converted it from a jpg to bmp. to do this i just changed the picture name from .jpg to .bmp, would a proper file converter tool be more appropriate?