Cant change Windows 7 wallpaper

I have a very strange problem in one of the windows accounts of my computer which is using Windows 7 Ultimate N.
When I go to personalize and change the wallpaper, the wallpaper doesn't change. I even try to change the themes but the themes change everything but the wallpaper. This happens in only one user account. Other accounts are working fine.

Please help me if you can. I'm stuck with one wallpaper! :crybaby:

quite strange:rofl_2:

restore ur system to a previous date and i hope all will be fine:thumbup1:

good luck:cool:

You can restore your computer system with your bootable disk and so if system have missing any system file it can install it through system restore and all function will be perform correctly.