You appear to be just wanting to complain. We've given you several alternatives to do clean installs, which you have completely ignored and just keep repeating the same misinformation again and again.
Most people do not have any trouble with upgrades. It's strange that you have so much trouble on multiple machines. And you refuse to follow any of the suggestions you are given. Makes one wonder.
Obviously, since you respond so quickly, you must have a lot more time on your hands than those of us that cannot afford to spend useless time on an update I really am not that interested in.. After spending a number of weeks, back when this initially came out, perusing this forum and many others, trying every alternative to updating, I finally gave up as they all give me the failure error. I will admit that I have a heavily loaded machine with LAMPS and other web software that may be causing the failures, but without a failure message that actually provides where in the process it failed or what it failed on, I have been given no clue as to what I might need to uninstall to get it done.
I haven't been back on this forum complaining, since last year, but only here now because I am getting tired of have this stupid script continually update to our taskbars. Maybe Microsoft should have made this an optin process without forcing scripts into our working os's.
Anyway, Coastalguy, your original question in this thread was why doesn't Microsoft allow a clean install of Windows 10. The answer to your original question is that Microsoft does allow you to clean install Windows 10 - they added that ability in the November update.
Define validation? Once activated, your PC will get a Digital Entitlement for Windows 10 on that hardware. That Digital Entitlement is stored on the Microsoft activation server, not in the motherboard BIOS. If your PC shipped with Windows 8, 8.1 or Windows 10 factory installed, there will be a product key embedded in the BIOS. Those PC's still have to activate online though. As of right now, the current Windows 10 install media will read and use those embedded OEM keys. Once the free upgrade offer expires though, those Windows 8 and 8.1 keys will not work for first time activation of Windows 10. Windows 7 PC's do not use OEM embedded keys period. Never have never will. The product code is only ever stored in the currently installed OS. Upgrade from 7 to 10 and they are detected. Do a clean install and there is no key to be detected, you have to enter it manually.
There are many reasons for a failed upgrade. Installed software like third party anti-virus can muck things up. Corrupted system files, etc can also throw a wrench in things. In a perfect world every one would work but that's not the world we live in. People do things to their system to tweak it like reg edits, theming software, etc. Anyone of those can break things then the upgrade software decides the safest thing to do is to do nothing.
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