Go on microsoft.com
Download the latest Windows Media player. In the process, you'll get a product key. Take note of it.
Install Windows Media player.
When asked, enter the produck key for Windows Media player.
Windows 8 is now totaly registered.
Alternatively, you can do a search for "remove WAT".
It's a small utility that was made just for the case where the Windows Activation Technology goes wonky... It totaly remove that technology and report "Genuine" to all tests.
Electro
January 2014