How to Change the Start Screen Background in Windows 8
 

Windows 8's new Start screen has been hotly debated since the operating system launched in preview mode earlier this year. Acknowledged by some as a bold step into the tablet market, and criticized by many others who prefer the familiar desktop experience, the new 'Modern UI Style' home is here to stay. But beyond not offering a way to bypass this screen (not without the help of third-party utilities), surprisingly Microsoft is also limiting your options when it comes to customizing the Start screen's appearance. You can choose from a couple color schemes and 10 stock background images, but that's about it.

http://www.techspot.com/guides/598-c...ound-windows8/