While Mary Jo mentions only retail product keys, the method seems to work with all kinds of product keys including OEM keys. Anyone who missed the deadline may still take Microsoft up on the free upgrade offer provided that they have a product key for a previous version of Windows. We don't know when the loophole ends and free Windows 10 upgrade offer expire for good for Windows 7 and 8.1 users. One explanation is that it feared public backlash after stating over and over again that the free upgrade period ended on July 29, 2016. It is unclear why Microsoft does not acknowledge the issue. It would also explain Microsoft's answer to Mary Jo Foley's question. This would mean that the option is only a temporary one, and that it will cease to be an option at all in the near future. Mary Jo's guess is that it simply takes a while to get things sorted out on the backend. Microsoft may decide to close the loophole at any point in time though but since it does not even acknowledge the issue, there is a chance that the loophole remains an option for the foreseeable future.

Windows 10 1607 serial key