Microsoft is adding an Activation Troubleshooter to the Windows 10 Anniversary Update. The new Activation Troubleshooter will help users resolve the common issues related to Windows 10 activation. Microsoft is making it easier for users to activate Windows 10 after hardware upgrade.
At present, when you activate Windows 10, Microsoft links the activation to the hardware of the computer. This way, if you reinstall Windows 10 it will automatically activate again by matching the hardware signature. Windows 10 fails to activate if you make some changes to the hardware and Microsoft can no longer recognize the device.