If the desktop background or wallpaper not showing or has disappeared ... The type of background of your desktop might be set to Solid color and black or the wallpaper you have selected might ...

Windows has included a variety of wallpaper images for the desktop background from the beginning, but it is also possible to set a solid color that displays only the color selected from the color ...

If your Desktop Background appears Black ... you might have mistakenly selected the Solid color option on these settings. Check if you have by chance set a solid black color for your background.