I hope this thread helps others who were contemplating buying the upgrade license but haven't bought it yet because of the lack of clarity on whether a person can do a clean install using the license they'd buy for $39.99.
Well the simplest answer is yes you can. You can either do it by the registry workaround to change MediaBootInstall from 1 to 0 @ HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/
But the cleanest method that I have tried this weekend with success, is what I want to recommend to all fellow Neowin members.
Buy the license key using the upgrade advisor application.You don't need to download the ISO file. Download a legit ISO of Windows 8 Pro (MSDN/Technet) from your favorite torrent and install using the license key you just bought. Not only you will be able to install it but Windows will activate without any trouble.
I hope this makes frontpage so more and more people know they can do a clean install and how!







