Registry: can't control Desktop Background Slideshow in registry?

Just a rough test:

1. No slideshow on desktop;
2. Backup the registry file;
3. Turn on the slideshow (Desktop - Personalize - Desktop Background - Select All - Save Changes);
4. Run the backup registry file;

The desktop starts with the original picture (the desktop wallpaper picture originally used) and still loops through the directory containing the original wallpaper.
No changes made by the registry file.

The slideshow (if wanted to turn off) isn't really controlled by the Registry?

Found.
Can't change desktop background in Windows 7

The first solution works. Yet, the second doesn't. Still not controlled by Registry.

For those who need to do this task like me, you may:

1. Include this script in a batch file:
2. Run the batch file;
3. Restart.