The reason I'm posting this is because of some statements I have seen in various threads. If you did a clean install of Windows 10 using one of the serial numbers available on the Internet. You will NOT be able to use that forever. It will not upgrade to a/the final version of Windows 10 that you can keep using. If you did an in-place upgrade using the Insider Program it will get the final upgrade and you can continue to use it. Again, if some people didn't quite understand. To continue using Windows 10 going forward you must have upgraded from, (in the case of the Surface) Windows 8.1. A clean install will stop working after the last preview version expires unless you purchase a copy of Windows 10.