This information may interest you if you do wish to keep a record of it: The 12 unused Windows 7 or Windows 8.1 - Windows Help - Microsoft Windows 8/8.1 The Product Key on preinstalled Operating Systems (HP, Acer, etc) is embedded in the BIOS in the Motherboard, so that the lost and/or worn C.O.A. Product Key consists of 25 digits, divided into 5 groups of 5 digits and the layout looks like this:
