Installing W10 from USB flash drive

[Lee Harvey]

I'm interested in the W10 free upgrade from a usb ISO image. I now have W7.
A couple of questions concerning the W10 installation from a bootable usb ISO image - will the hard drive require prior repartitioning, and what do I do when the install process asks for the license key ? AS I recall, installing W7 without a key only allowed 30 days of use.

 

[Trouble]

W10 free upgrade

The "free upgrade" is just that an upgrade and no license key is required, assuming a previously qualifying legitimate copy of Windows from which you perform the "upgrade".
As far as the ISO....
It is not, in an of itself bootable, so you would have to mount it and perform the in-place upgrade by clicking "setup.exe" from the mounted ISO, (easy in Windows 8.1 not quite as easy in Windows 7).
You might be better off, using the ISO to create installation media.
You can use ImgBurn to burn the ISO to DVD or Rufus to burn it to a USB ThumbDrive.
Again, once you have created the installation media then clicking setup.exe from within your current version of Windows will start the upgrade process.