: You can still download the Windows 8.1 ISO file directly from Microsoft for free if you already have a product key [16].
: If you have a computer that originally came with Windows 8 or 8.1, the product key is often embedded in the motherboard (BIOS/UEFI) and will activate automatically upon reinstallation [31]. Key Reasons to Upgrade Instead of Buying buy windows 8.1
: You may find old "boxed" copies or remaining digital licenses at third-party retailers like Electronic First [10]. Be cautious when buying from unknown secondary markets to avoid counterfeit or invalid keys. : You can still download the Windows 8