Windows Media Center for Windows 8 is available as an installable upgrade from Microsoft, $9.99 for users of Windows 8 Pro, $99.99 for users of standard Windows 8.
1) Open the System information screen by typing "System" from the launch screen, changing the filter to "Settings" and clicking on the "System" icon.
2) Click on the "Get more features with a new edition of Windows".
3) If you have a product key for Windows Media Center already, select "I have a product key"; otherwise, select "I want to buy a product key online".
4) Select "Windows 8 Media Center Pack".
5) Enter billing information.
6) Accept terms and conditions and click "Add Features" to install.
WARNING: Windows 8 will forcefully restart the computer without warning during the install process. Make sure you do not have unsaved work.