Are you trying to use a particular image as your wallpaper? If yes, have you checked to make sure the image is on your computer? If you are having trouble changing the wallpaper then do the following:
1. Open Display in Control Panel.
2. On the Desktop tab, do one or more of the following:
• Click a picture in the Background list. In Position, click Center, Tile, or Stretch.
• Click Browse to search for a background picture in other folders or on other drives. You can use files with the following extensions: .bmp, .gif, .jpg, .dib, .png, .htm. In Position, click Center, Tile, or Stretch.