Step 1: Download the Windows Media Creation Tool from Microsoft's Windows 8 installation media homepage and then click on Create media button to begin the download. Steps to download Windows 8.1 Pro ISO legally without product key Users are advised to proceed at their own risk. IBTimes UK will not be held liable for any damage to device during or after the Windows 8.1 Pro software installation. With due credit to folks at Redmond Pie, it is now possible to do a clean installation of Windows 8.1 rather than a direct upgrade that can cause stability and performance issues. Windows 8 users will no longer need a licensed product key for upgrading to the latest iteration of Windows 8.1, as Microsoft has recently rolled out the Windows Media Creation Tool, which allows users to create an ISO or bootable USB drive for installing Windows 8.1 Pro.