Your old Windows 7 or 8.1 key won’t work in Windows 10

Aug 3, 2015 05:02 GMT  ·  By

Now that Microsoft has finally started offering the free Windows 10 upgrade to users across the world, we’re seeing quite a lot of people trying to clean install the new operating system and thus avoid the painful process that the upgrade could turn out to be in case of compatibility issues or any other problems experienced during download and install.

And while the clean install worked for every single version of Windows released in the past, it doesn’t work for Windows 10, so you must not attempt to clean install Windows 10 without upgrading first!

The reason is as simple as it could be: the product keys you have for Windows 7 or 8.1 won’t work in Windows 10, and in order to benefit from the free upgrade, you need to perform the direct upgrade first.

How Windows 10 activation works

Microsoft explains how exactly this process works:

“Once your device upgrades to Windows 10 using the free upgrade offer and activates online automatically, an entitlement is registered to your PC’s hardware for your edition of Windows 10.  (If you go to Settings  >> Update & Security >> Activation says ‘Windows is activated.’)  Now you will be able to clean install (i.e. boot from media and install Windows 10) the same edition of Windows 10 seamlessly without having to enter a product key.”

In other words, once you perform the direct upgrade to Windows 10 and the operating system is activated, you can do the clean install how many times you want, as the generic product key that’s being users for your system is then automatically re-used to activate it once again when you get back online.

“You CANNOT activate Windows 10 using a Windows 7 or Windows 8/8.1 product key. Upgraded Windows 10 PCs do NOT use unique product keys for Activation - all upgraded Windows 10 PCs use the same generic product key that activates ONLY if you launched upgrade while booted in your Windows 7/8 system,” Microsoft adds.

As far as new hardware is concerned, Windows 10 doesn’t bring anything new to the table, so if you make significant changes to your hardware configuration, you might have to contact Microsoft to re-activate your device.