For Windows Internet Explorer
Right-click on the image you would like and select "Set as Wallpaper."

For Windows and other browsers
Right-click on the image you would like, then select "Save as" and save the image in windows folder. Change the saved image from JPEG format to BMP format using paint software etc, then right-click on the desktop image and select "Property." Choose the saved image file from the wallpaper lists and click "OK."

For Mac OS
Right-click for a while on the image you would like, then select "Save as"and save the image on your computer. Go to "Control Panel," then to"Appearance," next to "Desktop" (for OS-X, go to "System Environment"and select "Desktop") and choose the saved image file from the wallpaper lists.