The way to clean install Windows 10 is after upgrading first
This is important as once your computer upgrades and activates, your Windows 10 copy along with your hardware details are registered with Microsoft on their servers. Once you have upgraded to Windows 10, either via Get Windows 10 app or ISO, open Settings > Update & Security > Activation. Ensure that it says Windows is activated. If not, click on the Activate now button and activate it. An entitlement is registered to your PC’s hardware for your edition of Windows 10. If you do it this way, you will be able to clean install Windows 10 by booting from an installation media like a USB. You wont even be required to enter a Product Key now, since te operating system will automatically pull your activation details from Microsoft’s servers. A few important points to be remembered: During or after setup is completed, Windows 10 will activate itself automatically, online, with the same edition of Windows 10. If Windows 10 is not activated, click the Activate now button and activate it. If it does not work, click for a couple of times – maybe even after some time has passed. If it will not activate and maybe give out an error message, you may want to see these links:
Cannot activate Windows 10. Product Key blockedTroubleshoot Windows 10 Activation Errors.
This is the only way to clean install Windows 10 on your computer. You cannot use Windows 10 setup and try to use your genuine Windows 8.1 or Windows product key. It will not work. You might want to know at this point, that if your the hardware configuration of your Windows 10 device changes significantly. You may be required to activate Windows 10 by contacting Microsoft Support. You can Activate by phone or use the Contact Support app to seek support. How to directly clean install Windows 10 without upgrading first may also interest you.
