How to show Desktop Background as Wallpaper behind Windows 8 Start Screen
So you now have Windows 8, and having tough time figuring out a way to show the Desktop wallpaper as the background image to the Windows 8’s start (App) screen as well. This is a good idea to bring a nice uniform experience when you switch between the Start interface and the Desktop interface.
To begin with, right-click on the desktop and select “Personalize”.
In the Personalization window, click on “Taskbar and Navigation” located at the bottom left of the window.
Check the box that says “Show my desktop background on Start”. Click “Apply” followed by “OK”. Sign out and Sign in again to see the desktop wallpaper on the App Start screen.