Hi,
Thank you for writing to Microsoft Community Forums.
We will need the following information to help you further:
- Which edition of Windows is installed on the computer i.e. Windows 10 Home/Pro?
- Which version of Windows was installed on the computer before upgrading to Windows 10?
The error code 0x800704CF comes up when Windows couldn’t find a valid license for the device. I suggest you
to refer the article Get help with Windows activation errors and perform the troubleshooting steps mentioned in the article.
You can also try running the activation troubleshooter and check if that helps in activating Windows. Refer the article
Using the Activation troubleshooter.
Since you have a product key, you may try activating Windows using the product key. Refer the section
Activate using a product key from the article Activate Windows 10.
If the issue persists, I suggest you to get in touch with our Live Technical support team by calling them. Please refer the article
Global Customer Service phone numbers to get the Customer support number as per your country.
Regards,
Nikhar Khare
Microsoft Community - Moderator