Windows Systems: Under the wallpaper
thumbnail, click on either 800x600 or 1024x768. In the popup window, right
click on the picture and select "Set as Background".
Macintosh Systems: Under the wallpaper
thumbnail, click on either 800x600 or 1024x768. From the popup window,
drag the image to the desktop. Then use System Preferences >>> Desktop to
change the picture.