I have a Windows 8 Media Center Pack product key from the free promotion a year ago. I have activated it already, but since have uninstalled Windows 8. I am not looking to install 8.1 and try again. Having said that, how do I know what version of Windows my key is good for? I am sure I can go to the repository to get the download. Is there a proven way of upgrading to 8.1 and then using the key I have already to activate 8.1?