But, an exciting part about Windows media player 12 is that it has 5 hidden library background images, but you can’t activate it without changing some registry values.
To help you, here is a freeware, portable utility called Windows Media Player 12 Library Background Changer that lets you replace the default library backgrounds with the hidden one.
Just download it from here and run the tool. Select an image and apply it.
Download Windows Media Player Library Background Changer [via]