Why are you downloading from a torrent? I wouldn't touch one with an "activator" with a ten foot pole, god knows what else has been done to it. You can get official clean unmodified install media here, Create installation media for Windows 8.1 - Windows Help That install media will accept Windows 8.0 and 8.1 keys, even embedded OEM keys. You already have a product code, right?
no i dont have product key. actually the laptop is imported and hprecovery hard disk is formated and hp care centre they r not sending cds so i dun have it, i have downloaded windows 8.1 pro as u said sir