WMP12 Library Background Changer is a simple freeware tool which allows you to customize the background of Windows Media Player version 12. Actually this feature is build into Windows 7 but since its hidden you need to edit the registry. But using this tool, you can easily set the background images for WMP 12 library. You can either set predefined images in the tool or use the current Windows desktop wallpaper to even select any image.
Once applied, you need to restart your Windows Media player and you can see the image in action.
At any time you can always restore it back to the original background which WMP had when you installed Windows 7.
Download WMP Background Changer