I own a legit copy of Windows 8.1 Pro x64 and now it seems Windows 10 RTM came out. I heard many sides of the "Free Upgrade" story and still remain confused about it. I definitely will not be installing Windows 10 on top of Windows 8.1. I want a clean Windows 10 Pro installation. Is there any way I can get that for free somewhere? The 10240 is the RTM build, but so far it has still been released only as Insider PREVIEW version, hasn't it? EDIT: Does anyone know whether 7Stacks works with Windows 10?