I have an old Toshiba laptop that I don’t have a Windows operating system installed on. In addition, there is a Windows 7 product key located on the back of the laptop and contains a Certificate of Authenticity (COA).
I will use the Windows 7 product key to activate a Windows 10 computer.
Go to the Windows 10 search bar and type activation.
Select Activation settings.
In the activation window, click change product key.
Enter the product key and click Next.
Click Activate to continue with the activation process.
Now my Windows 7 license key has activated the Windows 10 computer.