So, I purchased a windows 8.1 pro key from a seller on bonanza last night. The seller had 95% positive reviews, so im hoping it wasn't a scam or anything. But I have tried EVERYTHING to get my bootable USB to work on the computer i just built. It keeps coming up with "The product key you entered does not match any of the windows images available for installation. Enter a different product key." I've went in and done the ei.cfg thing to skip product key, and it still says this/asks for one. I even went and made the PID.txt file in my sources folder, and it doesn't ask me to type it in anymore, it just pops up with that message, so i know it's reading the PID file..Everything i've tried has failed, can someone please help me..