Windows Media player is one of the good media players available for Windows. It comes with a default background for the libraries available. If you are looking to customize WMP12 with other backgrounds, then you can try out WMP12 Library backround switch, which is a freeware tool to change the library background in WMP. The tool comes with predefined backgrounds which you can use to switch the backgrounds in WMP12.
There are 5 images available for customization as well as the default one. Simply select the one you want to use and click the Apply button. Although the program is useful, the lack of custom background option is still disappointing.
WMP12 Library Background Switcher is a simple portable tool for all WMP users.
Download WMP12 Library Background Switcher