Please help me! So I recently bought Windows 8.1 Full Version from Best Buy and all, and I have my product key. I downloaded a trial version of Parallels and used my key onto that. 14 Days later (the length of the trial), I decided I don't really like Parallels, and I would rather use Bootcamp. The problem is, after completely uninstalling Parallels from my Mac, my Windows 8.1 product key no longer works. Whenever I try to activate it in Windows, it keeps telling me "The key didn't work. Please try again, or use a different key." Am I no longer able to use the key? What should I do? I really do not want to buy another one.