I just had my friends Asus Laptop that came with Win 8 Core preinstalled. I got the license extracted from the BIOS. I used my bootable USB drive that has 8.1 for clean installs. It did not ask me for any serial during install probably because I have read it detects the key from the BIOS and installs core or pro depending on the license it detects. It came with Core but it installed Pro. When windows came up for first time it was not activated and the key I had extracted did not activate it. I do many many clean installs on OEM computers so I don't want to do the 8 then 8.1 upgrade route that probably works but takes way too long. So why didn't my scenario work? Can someone point me to a guide that shows exactly what I need to do? I prefer to use the customers legal key. I know how to activate it our way. Thanks.