Instructions for Windows:

1. Choose the image in the appropriate size for your monitor
2. Once the image has fully downloaded, right click on the image and choose "Set as Wallpaper"

Instructions for Mac O/S 8.0:

1. Choose the image in the appropriate size for your monitor
2. Once the image has fully downloaded, hold down the mouse button until the "Save image as" option appears
3. Save image on your hard drive
4. Open the control panel "Desktop Pictures"
5. Remove current picture
6. Select file you have saved as your new picture
7. Choose "position automatically"