Win11 Cannot be Activated after Changing Motherboard

Replacing the motherboard changes the hardware identity tied to a Windows digital license, so reactivation is expected. Confirm that the installed edition is Windows 11 Pro; a Pro license cannot activate Home, or vice versa. Sign in with the Microsoft account linked to the activated PC, then open Settings > System > Activation > Troubleshoot. Choose “I changed hardware on this device recently,” select the old device, mark “This is the device I’m using right now,” and activate. If the device is not listed, choose Change product key and enter the retail Windows 8 Pro key that support verified. Remove that license from any other PC because a retail license can be used on only one device. Record the activation error code. If either method fails, use Contact Support in Activation and provide the error, purchase proof, and confirmation that the edition matches; community users cannot override the activation service