Hi,
If you make significant changes to your computer hardware, such as changing your motherboard, the license for your copy of Windows 10 may become deactivated.
Your Windows 10 license must be linked to your Microsoft account to reactivate it.
Check to see if your copy of Windows is already linked to your Microsoft account.
Open your Settings.
Click Update & security.
Click Activation.
If your account is already linked, you'll see "Windows is activated with a digital license linked to your Microsoft account" under Windows on the right. If you see this, you can skip to the next section.
Otherwise, click Add an account.
Enter your Microsoft account name and password. You may also need to enter the password for your local account (the password you use to log in to your computer). Click Sign in.
If your account was successfully linked, you'll see "Windows is activated with a digital license linked to your Microsoft account" in your Activation settings screen.
If you're still unable to reactivate your version of Windows, contact Microsoft. Explain that you changed the hardware on your computer, but the Windows license is not reactivating when you use Activation Troubleshooter.
Hope above information can help you.