The thing that has got me confused is the licensing for this free Win 10 upgrade. When I do the upgrade, where is my license key for win 10? Or do I even have one? If I want to do a clean install of win 10, would I even be able to do so? I googled around on this before and the best I came up with was that MS says they intend for clean installs to be possible, but I don't see how.