Hi,
Your steps seems no problem.
Make sure to disable the virus checking software and disconnect the laptop internet before upgrade.
Another thought is OEM vs Retail and there may be restrictions on OEM upgrades. If it's an OEM key, it may be not useful for upgrades
You could contact the manufacturer to see what they say.
To upgrade from Windows 10 Home to Windows 10 Pro and activate your device, you'll need a valid product key or a digital license for Windows 10 Pro."
For your reference:
https://support.microsoft.com/en-us/help/12384/windows-10-upgrading-home-to-pro
Hope above information can help you.