Prevents users from changing the background image shown when the machine is locked. By default, users can change the background image shown when the machine is locked. If you enable this setting, the user will not be able to change their lock screen image, and they will instead see the image set prior to enabling this setting. Fix: (1) GPO: Computer Configuration\Administrative Templates\Control Panel\Personalization!Prevent changing lock screen image (2) REG: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Personalization!NoChangingLockScreen