having a background will slow down your pc, so its best to leave it but anyway here
1. Run "Regedit".
2. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ Windows\CurrentVersion\policies
3. If you see a folder (key) "ActiveDesktop" select it. If not, make a new key and label it "ActiveDesktop".
4. If you see "NoChangingWallPaper", double-click the DWORD value and set it to "0". Otherwise, you need to create a new DWORD value of "NoChangingWallPaper" and set it to "0".
5. Try changing your wallpaper. If this fix doesn't solve the problem, you may also need to make the above registry changes at location: HKEY_CURRENT_USER\Software\Microsoft\ Windows\CurrentVersion\Policies .