I have Windows 8.1 Pro installed (fresh install) and activated. I then added the Media Center feature and successfully activated. Please note that I'm using the Media Center key I purchased when I was on Windows 8. The Windows 8.1 Pro key is however a retail key, not an upgrade key, which I bought later.
Occasionally, I find that Windows 8.1 would deactivate itself from time to time for unknown reasons. Sometimes it does that when I change some BIOS settings. I normally resolve this by using System Restore. However, on my latest occurrence, for some odd reason, there is no available restore point for me to restore to.
Now, when I go to the Activate Windows screen, I'm asked to enter the product key. Entering both the Windows 8.1 Pro key and Media Center key fail with the following message,
"The key can't be used to activate this edition of Windows. Please try a different key"
"The key didn't work, please check it and try again, or try a different key."
I tried the "slmgr /ipk" method and I get the following error,
0xc004f069 for Windows 8.1 Pro key
0xc004f061 for Media Center key
How do I resolve this issue?