Win7 when prompted to change the desktop wallpaper, how to do

In the Win7 system to replace the desktop wallpaper error, prompt: Can not set the picture as wallpaper, an internal error. How do we solve this problem?
1. First double-click the desktop “Computer” icon, and click “Organize”-“ Folder and Search Options” in the interface.
2. Then switch to the “View” tab in the window, remove the "protected operating system files" in the advanced settings column, check and then select “ show hidden files, folders And drive & rdquo; click & ldquo; OK & rdquo;.

3. Then open C:Users user name AppDataRoamingMicrosoftWindowsThemes This path (where the user name is the user name your computer is using, enter it yourself), after opening, delete all the files inside.
4. After deleting, right click on the desktop and select “Personalization”, and change a theme in it, then you can change the wallpaper.
5. Then use the second method to hide the files.