Instruction to download

MAC OS9:
Ctrl + click on the image to save to your hard drive.
Under the Apple menu, open Control Panel/Appearances.
Click on the Desktop tab and on the bottom right hand corner, click 'Set Desktop.'
Choose the image you want to place on your desktop.

MAC OSX:
Ctrl + click on the image to save to your hard drive.
Open your System References and click on the Desktop icon.
Drag the image you want to place on your desktop into the 'Current Desktop Picture' thumbnail.
 
PC:
Open the image in your web browser.
Right-click on the image and select 'Set as Wallpaper.'