Windows 10: My background turns back to a particular old wallpaper if left for few minutes or restarted.

When I personalize my background with new picture or the default given once. Within few minutes it turns back to another particular wallpaper which i once kept as my background. This doesn't happen in solid color, themes and slideshows. I have deleted this picture already but now i cant find how this happens and where it is located.

:)

 

Look for particular wallpaper

In this Video is a commercial showing win7 wallpaper. In particular the one at 18 seconds where he suggest that the wallpaper is popping out. But I can't seem to find it anywhere.
Does anyone have any idea where it is?
Edit: I found it. It's part of the Aero Themes. *Eek!

Another edit:
Here's a to unlock other theme packs if you didn't know about it.
Enjoy!

 

Desktop background gone black after a few minutes of use on laptop.

Hello,

Desktop background and taskbar going black could be due to software conflicts.

We would like to know some information to better assist you with your concern:

• What troubleshooting steps have you done so far?
• Did you get any error messages or error codes?

In the meantime, we suggest that you try to check if the "Show Windows Background" option is turned on. Follow the steps below:

• Open Settings in the Start menu.
• Go to Ease of Access, then on the left side, click
  Other options.
• Turn on Show Windows Background and check if it works.

We will wait for your reply.

 

Windows 10 background wallpaper turned black

Hello,

My Windows 10 background wallpaper turned black when I was running a code on my laptop. I restarted my machine, but it stayed black and did not return to the previous wallpaper. What is the reason? Does it mean that my files are damaged?