Windows 8 is designed especially for tablet, touch pads and all other touch based gadgets. The basic idea in windows 8 is to sync up your computer, tablet, smart phone and all other devices at the same time. It is necessary to activate windows 8 with an activation key. After activation, Windows 8 can update itself from Microsoft online servers automatically. There is also an option to change the current activation key and use another one. Here, we will teach you how to change windows 8 activation key by using the command prompt.