How to set the default desktop background in win 10

1. Enter [Background Image Settings] ① in the Windows search bar, and then click [Open] ②.

2. In the background, you can choose a picture, a solid color or a slide ③ to create a picture. You can also click Browse ④ to select other pictures as the background.

3. If you want to change the display mode of the picture in the background, you can choose Fill, Full Screen, Expand, Side by Side, Center or Cross Screen in the display mode selection.