I've found what I feared!
Win 7 is no longer 'supported'. The link does not seem to lead to an .exe file compatible with Win 7. [The site wanted to get you to download all sorts of other stuff!]
The downloaded Win 10 file which I dragged to the USB stick is not compatible with Win 7.
The computer does not link to the printer! Even though the icon for the HP printer shows in the available printers.
I think the end of the trail has come!