Remove Picture Location history from Personalization panel
The default locations like Windows Desktop Backgrounds, Solid Colors, etc, will also be displayed. To remove the list of non-default locations, here is what you can do: Open regedit and navigate to the following key:
Now on the right side, you will, other than “Default”, see some values from 0-9. These represent the directory path where images are stored. To clear an entry from the Wallpaper Location drop-down list, right-click on the registry value & click Delete. Remember to create a system restore point before opening the Registry Editor.