Windows Wallpaper issues !!?! Strange one!

[gazzab]

The wallpaper on my XP Media centre PC is set to a photo - I can see the pic briefly during start up. Once up n running I get a grey background on top of the photo. I know it is on top as I can drag the toolbar down and it shows me part of the phot underneath. If I go into control panel and display then I cannot change any settings ie it wont let me select a background wallpaper. It will let me select another style ie changes the grey background to blue etc..
The PC came with media centre pre-loaded and so I am not sure if I can (or should) try and reload the OS.
Any ideas?
thanks!!!
Gary

[thepassenger]

Right click on the desktop, select properties, select Desktop tab.

Will it let you select a picture on this tab? If not it could be that your not running as administrator (to be honest, not being allowed to change the piccie would suggest a guest account).