If you do not want to pay any fees, it is best to back up your Product Key or Activation Key in case something goes wrong. In the article below will guide you two ways to back up Product Key on Windows 10, 8 and Windows 8.1 product key.
1. Backup Product Key on Windows 10, 8 and Windows 8.1
Follow the steps below to back up your Product Key on Windows 10, 8 and Windows 8.1:
Press the Windows + R key combination to open the Run command, and then on the Run command, type "notepad" into it and press Enter or click OK to open a new Notepad.
On the new Notepad, copy and paste the script
Choose a location and put a name for the file and remember to add the extension .ps1 (remove the .txt extension).
Click Save to save the file.
Right-click the file you just created, then select Run with PowerShell.
PowerShell will ask you to confirm whether you want to keep a copy of the product key on your computer. Enter Y then Enter to confirm.
The product key that you backed up on Windows 10, 8.1, and 8 will be stored in the WindowsKeybackup.txt file on your computer.
2. PowerShell Script to back up Product Key on Windows 10, 8.1 and 8
In addition to this you can download the PowerShell Script to back up Product Key on Windows 10, 8.1 and 8.
Extract the WindowsKeybackup.rar file that you just downloaded.
Right-click on the file named windowsbackupproductkey.ps1 and select Run with PowerShell.
Enter Y in the PowerShell window and press Enter.
And now you can see the Product Key you have backed up on Windows 10 product key, 8.1 and 8 computers.