Now open up the 'Desktops & Screen Saver' preference pane in the System Preferences in one of the two ways described below.

• Control-click on the desktop (your actual desktop, not the file you just downloaded). Select "Change Desktop Background..." from the contextual menu that appears. Select the 'Desktop' tab in the preferences pane that appears.
• Or, choose "System Preferences..." from the Apple Menu, and then click on the icon for "Desktops & Screen Savers". Select the 'Desktop' tab.

Next, click on the "Pictures Folder" item from the list. In the browse pane you should now see the desktop wallpaper you just put into your Pictures folder. Click on it and your desktop will immediately change to the new one!