If you are using multiple monitors on your Windows 10 PC, you can easily set separate wallpapers as the background of each display. To set different wallpapers for dual monitors in Windows 10, do as follows:
1. Make sure you are on the Desktop. (A quick shortcut to jump to the Desktop is pressing Windows Key and D at the same time)
2. Right click on an empty place, and then click the Personalize option (you may also follow this path: Settings > Personalization > Background)
3. Set the Background mode to Picture and then either choose from default Windows 10 pictures or Browse from your storage
4. Now, right click on the picture you want to set as the Background Wallpaper. As you see, you have the option to set this picture for the first monitor or second monitor or your both monitors.
5. Choose a picture as the background wallpaper of your first monitor and then another picture for the second monitor.