If you are an administrator of a Windows 7 based computer, then you can force same desktop wallpaper of your choice for all users. The users should be standard users and should not have administrator rights or they would be able to change the desktop wallpaper back. Here is how :
- Press the key combination Windows Key + R to open the Run dialog. Type gpedit.msc in the Run dialog and press Enter.
- In the Group Policy Editor, select in the left side tree view : User Configuration → Administrative Templates → Desktop → Desktop.
- In the right side, find a value Desktop Wallpaper. Double click on it to edit it.
- In the Desktop Wallpaper settings window, select Enabled on the top-left. Type in the full name of the wallpaper file. The wallpaper file should be either JPEG or BMP file. You can select the wallpaper style from the dropdown list.
- Then click on the OK button to save the chages
Now all the users on your computer will have the same desktop wallpaper and they will not be able to change the wallpaper or the wallpaper image file.