Contrary to past statements, Microsoft has begun offering ISO and USB flash drive install options for Windows 10 desktop editions.
The tools work differently than past Windows installers however, in one key factor – they must be run from inside the Windows installation you currently have.
The ISO and USB flash drive tools do what we previously reported one could do unofficially – they download the encrypted images (what Microsoft calls ESDs) from Windows Update, and then decrypts them, finally converting them into writable installer medias.
The resulting ISO and USB flash drives can be used to create clean installs for Windows 10, but only with a retail Windows 10 product key. Even a BIOS key from Windows 7 or Windows 8/8.1 will not work when booting from the drive.
Installing from inside Windows, however, is a different story. One can simply run the setup.exe from inside Windows, and the installer will upgrade the Windows install in-place. Various options are offered, including a “clean” install where the user account and files on the machine are removed. However, it’s not the same as a bare drive installation.
To accomplish a truly clean install, with a Windows 7 or 8 license, one must run the Windows 10 installer, and then proceed to run the restore tools inside the final Windows 10 installation for a clean wipe-and-reinstall. The licensed Windows 10 install will then erase the hard drive, and use the Windows 10 install media to reinstall, finally copying back the upgraded license key and activation codes.
These install steps can be confusing to some. There are already reports of many who have, over the past 24 hours, booted the restore media and ignored the product key prompts. Windows 10 will install if booted from the install media, but will eventually fail Windows Activation. The only fix at that point is to obtain a valid Windows 7 or Windows 8 recovery drive, and then reinstall that Windows version, finally upgrading to Windows 10.
In short, it’s not as clear as in past versions of Windows. We encourage all PhoneNews.com readers to make sure they create a valid recovery drive for Windows 7, 8, or 8.1 before attempting to install Windows 10.
We’ve upgraded over a dozen systems over the past 24 hours. Of which, three resulted in unusable systems; two produced a black screen, and would not boot… one resulted in drivers that could not connect to the Internet or use the integrated graphics card properly.
