• When the image comes up in the browser window, right-click on the image.
• From your browser's pop-up window, select "Set as Wallpaper"

MAC

• Click and hold on the image, then save it to your hard drive.
  
• In your Desktop Pictures control panel, click "Select Picture" (if you already have a picture, click "Remove Picture" first, then "Select Picture") and choose the image.
  
• Click "Set Desktop" and close the control panel.