Most of us enjoy displaying out favorite Desktop Background or Wallpaper on our Windows Desktop. But, if you find for some reason that you cannot change the desktop background in Windows 8 or Windows 7, you may try some of these troubleshooting steps.
Cannot change desktop background Windows 7 | 8
Before you begin, please check if you have installed and third-party customization software and if it is restricting you from changing the desktop background. If so uninstall it and restart your Windows PC.
1] Open Control Panel and select ‘Ease of Access’ Center. Then, click on ‘Optimize Visual display’ link. Scroll down until you find ‘Make the computer easier to see’ section. Once found, make sure that
Remove background images (where available) is unchecked. Save, Apply, Exit.
This should help!
2] Open you Power Setting in Control Panel. Open
Power Options > Select your power plan > Change plan settings > Change advanced power settings > Expand the Desktop background settings option > Expand Slide show
Ensure that the Plugged in option is set to Available.
3] If the above option too fails, maybe your TranscodedWallpaper.jpg file has become corrupted.
Open explorer and type the following in the address bar and hit Enter:
%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Themes\Here, rename
TranscodedWallpaper.jpg to
TranscodedWallpaper.old.
Next, double-click slideshow.ini file and open it with Notepad. Empty its contents. That is, select all the text and delete it. Save the changes. Close explorer windows.
4] If not, try this. Run
regedit and navigate to the following key in the Registry Editor:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies 
Right click on
Policies >
New >
KEY > name it as
ActiveDesktop.
Next in the right side, right-click > New > DWORD > name it as
NoChangingWallPaper.
The DWORD value
1 will restrict change in desktop wallpaper. To allow change
give it value as 0.
Reboot.
5] Alternatively, you could open the
Group Policy Editor, by typing
gpedit.msc in Run box and hitting Enter.
Navigate to User Configuration > Administrative Templates > Desktop Click Desktop again. Double-click Desktop Wallpaper.
Ensure that the Not Configured option is selected. This will enable the option to change the desktop background.
source:twc
