With Windows 10, the product key has gradually become less important, because since 2016 Microsoft has offered digital licences. These allow you to install the operating system without installation or boot media and activate it through your Microsoft account. When a new installation starts, the system automatically detects the licence by reading it from the hard disk.
Of course, if you need to replace the hard disk, your digital licence will be lost, so before replacing the disk and reinstalling the operating system, I recommend running the following command to read and note down the current product key of your Microsoft licence.
Run the following command in the Command Prompt (cmd); as soon as you confirm with ENTER, your product key will be displayed on screen.
wmic path SoftwareLicensingService get OA3xOriginalProductKey
Personally, I have needed to run this command on machines where the operating system came pre-installed but activation could not be completed. Running the command retrieved the product key, which I copied and entered manually in the “Change product key” screen, and everything went smoothly.
Enjoy!
