Windows Upgrade Help and more

You could also try using the Activation Troubleshooter again, but this time choose the "I changed hardware on this device recently" option. Another option is to contact Microsoft support directly—they can often push a reactivation through on their end.

+1 You could also try manually entering your Windows 10 product key again in the activation settings. Another option is to run the Windows Activation troubleshooter from the command prompt as an administrator.