You need to backup and restore an activation because every time you format and reinstall Windows you need to activate Windows again. My tutorial explains how to backup and restore an activation license of Windows, Office & Server. For activation you look for a valid MAK-Retail key, calling Microsoft or waiting for a KMS server to go online etc. Sometimes when you activate Windows with a previous key then you have a problem with activation and get the error message “This key has a limit of activation or is blocked. But if you want to reinstall Windows or if you switch Office and don’t want to lose the activation then you can create a backup of the activation and then reinstall Windows then restore the activation.
This activation method backs up and restores the Windows 10, Server 2016 activation as well as Microsoft Office activation.