The main advantage of a Skin Pack over a Background Changer, is that the skin pack changes the complete look of your operating system. From the taskbar to the file and folder icons, everything is transformed into something new and different from what you used to have. You can install a different skin pack after sometime to keep the look fresh.

Android Jelly Bean Skin Pack for Windows

make sure that you uncheck the installation of Babylon toolbar to avoid getting unwanted software in your computer,see the installation process screen shots.Check to install the UXTheme Patch, Files and Extras to install everything that comes with the skin pack

Download The Android Jelly Bean Skin Pack for windows7 32-bit from here
 

Android Jelly Bean Skin Pack for Windows 8

Android Jelly Bean Skin Pack for Windows 7

Android Jelly Bean Skin Pack for Windows xp

The transformation pack comes with built-in Android style gadgets for Analog Clock widget, Digital Clock and Weather, Weather Forecast, Volume changer, Google search bar and shortcuts for accessing different folders.

Android Jelly Bean theme for Windows xp

Android Jelly Bean theme for Windows x7