Three times I have tried to go from my legit win7 to win10 but it fails C1900101-20017 - so I cannot get win10. I can do a clean install via the downloaded iSO but obviously cannot get it activated becuase I do not have a win10 key. From what I have read there are two relatively weak issues by it not being activated, otherwise it is fully functional (update wise). So ... why activate win10 - just do a clean install?