On a computer that is provided with a desktop kind of user interface, wallpaper is the background pattern or picture against which desktop menus, icons, and other elements are displayed and moved around. A wallpaper image can be in a BMP, JPEG or a GIF file format. Adding different wallpapers to you computer allows you to change the background image of your desktop.

To setup new wallpaper, follow these steps:
• Click on the thumbnail of the wallpaper you like.
• When it opens on the popup window, click 'Right mouse
  button' on top of the image and select 'Save Image As...'.
• Navigate to your Desktop and click the 'Save' button.
• Close all windows.
• Click 'Right mouse button' somewhere on desktop.
• Click on 'Properties' and Choose the 'Background' tab.
• Click on 'Browse' button
• Find and highlight the image you saved.
• Click 'Open' then Click 'Apply'.