What this means is that you can download the Windows 10 Setup media—which is always the latest version, so you’ll get Windows 10 version 1709, or the Fall Creators Update, at the time of this writing—and perform a clean install of the OS on any PC. And then you can activate that install of Windows 10 using an unused retail Windows 7, Windows 8, or Windows 8.1 product key. And it will just work.
https://www.thurrott.com/windows/windows-10/142616/yes-can-still-clean-install-windows-10-windows-78-x-key
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