Windows 10: "Unattend" Product Key error when doing fresh install

Hi all.
Was running Win 7 Home Basic; upgraded using to Win 10 but performance was poor.
So, attempted to use the Settings tool to "Reset" without keeping my files. The reset got stuck at 66% (how ominous) and then informed me that the reset failed and the pc shut down. When I rebooted, no OS was found. The Reset deleted the partition with Recovery options as well.

I installed Win 7 from another OEM disk and then downloaded the Win 10 setup to a USB flash. (I have my original Win 7 product key).
When I boot from the Flash, I get the following the error from Win 10 setup: "Windows cannot read the <Product Key> setting from the unattend file".

Is there a way to get it to prompt me for my product key? Is there any way to get past this error?
Thanks in advance.

:)

 

Reset/recover windows 10

Your machine is digitally registered with Microsoft, hence you do not need a product key. Just click "I have no product key" when commencing the re-installation. Things will fix themselves once the machine goes on-line.

 

Clean install an upgraded Windows 10 later with a new official build, later than build 10240

So would I be right in thinking that if I do a fresh install rather than an upgrade (getting the "something happened" error), will Windows 10 activate okay? Obviously I won't have a product key for Windows 10 and the key I have for my Windows 7 won't work.

 

Delete the file: Unattend.txt from the flash drive. (rename it to old_unattend.txt.old)

 

Hi. Thanks for the assist.
Tried this, but still getting the error.
There's a file called UNATTEND.DLL in the Sources folder. Is this the same file that I must rename? Can't locate a text file with that name.