Right click the desktop and go to Personalize.
Once the window pops up double click on something like "backgrounds" or "windows backgrounds"
It will display all of the wallpapers. When you hover over them you can see a check mark in the top left corner of the thumbnails. If you uncheck it, that wallpaper won't display. If you only want one wallpaper, just uncheck all but the one you want. Hope this helps.