Windows 10 Activation Error 0xc0020036
The typical cause is the issue is that the license key used for activation is incorrect. However, most users facing the problem confirmed that the key they possessed was genuine. The other reason is that when users upgrade from an earlier version of Windows to Windows 10, the previous license remained hard-wired to the system’s Registry. If you face this issue, try the following suggestions: If you encounter the Windows 10 activation error 0xc0020036, recheck your license key and install all pending updates in Windows. Thereafter, try the following troubleshooting sequentially:
1] Uninstall and clear the existing license key
In case you upgraded from an older version of Windows to Windows 10, it is quite possible that the previous product key has remained hard-wired there. In such a case, please deactivate and uninstall the previous product key and then enter the new one. This solution has helped a lot of users in resolving the problem.
2] Run Windows 10 Activation Troubleshooter
Run the Windows 10 Activation Troubleshooter and see if it helps you.
3] Contact Microsoft’s licensing activation center
If the problem is with the key itself, then the only resolution would be to contact Microsoft Support. Explain to them your problem and share the necessary details. If you have purchased a genuine license, the team will surely help you fix your problem.
If you need additional suggestions, check this post on troubleshooting Windows 10 Activation Errors. I hope it helps!