What the hell is going on with DeviantArt? I can't upload my software here, it says "To protect our users, deviantART does not allow archives which contain executable files, password protection, or other archives. Please remove these files from your archive and try again.". So, I have to point you to the external link
Desktop Background Tuner is my latest work. It allows you to change few hidden registry settings of Desktop Background feature in Windows 7 and Windows 8.
With Desktop Background Tuner you will able:

• Add or remove items into "Picture Location" combobox. I will call them "groups" for simplicity, ok?


• Add or remove folders to "Windows Desktop Backgrounds" group in Desktop Background settings.


• Add or remove folders to any other group you have added in "Picture Location" combobox.


• Add personal folder or add system-wide folder to group.


• You can control grouping of images. There are several settings available:
  
  • grouping by file author
  
  
  • grouping by file comment
  
  
  • grouping by date
  
  
  • grouping by file extension
  
  
  • grouping by Mime type
  
  
  • grouping by file name (non-localized)
  
  
  • grouping by file name (localized with desktop.ini)
    By default grouping is set to localized folder name. Now you can change it.

• You can change animation duration when desktop wallpaper changing. In other words, you can set speed of the fade effect transition.

Note: this trick is not available for Windows 8. Microsoft has removed animation duration option from registry and this settings has no effect in Windows 8.

• You can delete "Picture location" cache/history of Desktop Background option with one click.

Desktop Background Tuner is portable application and does not require to be installed. Unzip it and just run. If you are Windows 8 user, please use DesktopBackgroundTuner.exe from Windows 8 folder.

Click Here Download Desktop Background Tuner