At the time I didn't realize that, but then I needed to play a DVD with the laptop and noticed, that the OS is not capable of doing that anymore. After Windows 8 was released it didn't have much media capabilities. To fix that, couple months after the release Microsoft distributed Media Center Pack keys for free to anybody who wanted to request one. I got a couple of the keys and installed one into my laptop.
Anyway, the 8.1 upgrade forgot to mention that it would downgrade the installation back to non-media capable. That should be an easy fix, right?
After the 8.1 upgrade was completed, I went to "Add Features to Windows", said that I already had a key, but Windows told me that nope, "Key won't work". Nice.
At the time I had plenty of other things to take care of and the media-issue was silently forgotten. Now that I needed the feature, again I went to add features, and hey presto! It said, that the key was ok. For a couple of minutes Windows did something magical and ended the installation with "Something went wrong" type of message. The option to add features was gone at that point, so I really didn't know what to do.
The natural thing to do next is to go googling. I found an article at the My Digital Life forums, where somebody complained having the same issue. The classic remedy for everything ever since Windows 1.0 has been a reboot. Windows sure likes to reboot. I did that and guess what, during shutdown there was an upgrade installing. The upgrade completed after the boot and there it was, the Windows 8.1 had Media Center Pack installed. Everything worked, and that was that, until ...
Then came the 2nd Tuesday, traditionally it is the day for Microsoft security updates. I installed them and a reboot was requested. My Windows 8.1 started disliking me after that. The first thing it did after a reboot, it complained about Windows not being activated! Aow come on! I punched in the Windows 8 key and it didn't work. Then I typed the Media Center Pack key and that helped. Nice. Luckily Windows 8 activation is in the stupid full-screen mode, so it is really easy to copy/paste a license key. NOT!
The bottom line is: Media Center Pack is really poorly handled. I'm pretty sure nobody at Microsoft's Windows 8 team ever installed the MCP. This is the typical case of end users doing all the testing. Darn!