I bought last year an Asus laptop which was preinstalled with Windows 8 (non-Pro) x64 and had an embedded product key. Even once the harddrive was formatted, the setup read the key embedded in the chip and chose the non-Pro edition automatically so that clean reinstallation could be completed when an en_windows_8_x64_dvd_915440.iso disc was used. Then Windows 8.1 was released and its update followed it. Every time however I try to make clean installation of Windows 8.1 (with Update) using a disc of en_windows_8_1_x64_dvd_2707217.iso or en_windows_8.1_with_update_x64_dvd_4065090.iso, the setup cannot recognize the embedded key nor manual inputs of the key (read with RWEverything) can be accepted (invalid key). I don't want to start with en_windows_8_x64_dvd_915440.iso every time to reach "Windows 8.1 with Update". Help would be appreciated.