Step 1: Go into the Start menu > Settings > Personalization. Then expand the Background menu to view your options.
Step 2: Chose Picture to select a default picture, or to choose a picture of your own click Browse.
Step 3: To choose a solid color, choose Solid Color in the drop down menu and select a color in the color pallet.
Step 4: The last option, Slideshow where you can select a number of picture that will cycle of your computer screen. To do this, select Browse. You can even adjust how often the picture changes.