I'm helping my uncle with his laptop. It has Windows 8.1 on it and plenty of crapware. I'd like to reinstall Windows 8.1, however I only have a Windows 8 install media. I extracted the key with WinKeyFinder and tried to get the installation media through here, but it tells me the key is invalid. EDIT: ok WinKeyFinder doesn't support Windows 8 and returns crap. I used Magical Jelly Bean Key Finder, which returns the real thing; now the Microsoft installer tells me that key can't be used a commercial installation of Windows 8.1.
That said, I suppose the key is embedded in the BIOS (this is an Acer Ultrabook), the only question is whether that'll work with a Windows 8 installation media. If not, how can I legitimately get a Windows 8.1 installation media?