Even though your Windows 10 has a genuine key, it may fail to get activated.  The first thing you should do is run the Windows Activation Troubleshooter. If it doesn’t resolve the problem, let’s see what you can do next to fix this Windows Activation Error. While minor hardware changes don’t cause any trouble with activation if you have made any significant hardware change like replacing your motherboard, then its a problem. Windows Activation system will treat this as new hardware, and you will need a new license.

Windows Activation Errors 0xC004F211, 0xC004F213

There is an exception that Microsoft offers. If you connected to a Microsoft account prior to the hardware change, then you can re-use the same license key, and reactivate your Windows again. Microsoft calls it an Exception path. All you need to do is run the Windows Activation troubleshooter, and it will resolve the issue. In a rare case, even if you a Microsoft account available on the Windows 10 computer, if the Windows was never activated, this solution will not work. In case you have not connected your Microsoft Account with the Windows 10 computer prior to a major hardware change, then the only option is to purchase a new license. To purchase a new Windows license, select the Start button> Settings  > Update & Security  > Activation, and then select Go to Microsoft Store. After you have received your new license, go back to Update & Security  > Activation, and then select Change product key.  Update with a new key, and your Windows will be automatically activated. After this, make sure to create a Microsoft account or connect your existing local account to your online account. Once the system links the key, and the account, even if you change your hardware, you will not have to buy a new license in case of an activation issue. IT admins should note that there is a limit to the number of times you can reactivate Windows on your device. Also, If you don’t see any option to reactivate the license, and it’s a work computer, you should contact your organization’s support person.