Microsoft has fixed activation issues related to the Windows 10 upgrade.
Gabriel Aul, vice-president of the WDG Engineering System team at Microsoft, said in a tweet that those who have Windows 10 activated with the old hard disk drive should now be able to reinstall and reactivate.
This means if you have earlier used a legal copy of Windows 10 and performed a clean install, Microsoft will activate the new version for you. If the activation does not happen instantly, wait for a while. It should happen automatically.
With the availability of Windows 10 free upgrade, many users reported facing issues with Windows 10 activation. In some cases, server issues caused activation to fail. Some users wondered if the Windows 10 clean install will activate the latest version.
Nevertheless, the company provided details about the common errors of Windows 10 activation with possible fixes for each. You may try out the fixes to get started with the Windows activation.
Source: Microsoft News