If you try to activate your copy of Windows 10 and run into the Windows 10 activation error 0xc0020036, this article would be useful for you. This error ideally indicates that the copy of Windows may be hacked, but most of the users faced with the problem have confirmed that this is not the case.
The product key you entered did not work. Check the product key and try again, or enter a different one. (0xc0020036)
Windows 10 activation error 0xc0020036
The typical cause is that the problem is that the license key used for activation is incorrect. However, most of the users faced with the problem confirmed that the key they owned was genuine. The other reason is that when users upgrade from an earlier version of Windows to Windows 10, the previous license remained wired to the system registry.
If you are experiencing this problem, try the following suggestions:
- Uninstall and erase existing license key
- Run Windows 10 Activation Troubleshooter
- Contact the Microsoft Licensing Activation Center
If you encounter Windows 10 activation error 0xc0020036, recheck your license key and install any pending updates in Windows. Then try the following troubleshooting sequentially:
1) Uninstall and delete the existing license key
If you upgraded from an older version of Windows to Windows 10, it is quite possible that the previous product key was left there. In this case, please deactivate and uninstall the previous product key, then enter the new one. This solution has helped many users to solve the problem.
2) Run Windows 10 activation troubleshooter
Run the Windows 10 Activation Troubleshooter and see if it helps.
2) Contact the Microsoft Licensing Activation Center
If the problem is with the key itself, the only solution would be to contact Microsoft support. Explain your problem to them and share the necessary details. If you bought an authentic license, the team will surely help you to solve your problem.
If you need additional suggestions, check out this article on troubleshooting Windows 10 activation errors.
I hope it helps!