The volume license versions of Windows 8 Pro and Windows 8 Enterprise do not have an Add features option. Therefore, you cannot install the Windows 8 Media Center Pack on computers that are running these versions of Windows.
This behavior is by design. The Windows 8 Media Center Pack is intended for consumers only and is not available with volume license versions of Windows 8. The functionality that enables you to add this feature pack is not present in volume license media.
Volume license customers who require the functionality that is contained in the Windows 8 Media Center Pack (such as DVD playback) should look for third-party solutions that can be installed on Windows 8.
How to determine whether you are running a volume license version of Windows 8
Start an elevated command prompt. To do this, follow these steps:
Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.
In the search box, type cmd.
Swipe across or right-click the displayed Command Prompt icon.
Tap or click Run as administrator.
At the command prompt, type the following command, and then press Enter.
If the Description line in the output contains "Volume," you are running a volume license edition of Windows.
For example, the following lines indicate that you are running a volume licence version of Windows:
Description: Windows Operating System, Volume_KMSClient
Description: Windows Operating System, Volume_KMS_W8 channel