Many thanks for all the suggestions. I will try another install of W10 (having rolled back to the comparative luxury of W7) and see if I can overcome W10's incompetence.
More and more folks are posting about Win10 not seeing their printers or not installing the right printer drivers. In all cases, installing the Win8.x drivers and software from the printer manufacturer solved the problem.
What about when there aren't any w10 drivers under HP webpage? It happened to me yesterday with an HP Color Laserjet 2600n. The printer was detected by hardware manager (but not by anything else). There were two different drivers and neither of them worked well. Way to go Microsoft.
Man, it seems HP sucks these days. 90% of horror stories driver installation wise come from HP. Meh.
I said: "...if I can overcome W10's incompetence." I'll put it more simply. I will re-install W10 and then using the additional knowledge I have gained on this forum regarding installation of printers I will apply that knowledge and trust that it will get me past this particular show-stopping problem.
I'm not expecting W10 to behave in any different way and overcome the printers issue itself because it has been explained to me on this forum that W10 is incompetent when it comes to automatic installation of printers.
NB: I don't mean to sound tetchy, but I've just got up to find our aged cat has broken the habit of a lifetime and taken a comprehensive dump in the kitchen during the night. Just what I need before breakfast.
I experienced the same issue with a HP printer.
I did not use the software (never do) to "find" the printer
I always reserve an IP range for printers and other devices that are outside the DHCP pool.
On the outside of each printer I mark the IP-Address (I know that the printer is capable of showing it in the software, but this is faster )
First I ping the IP to make sure the connection is working
In Win 7 and 8(1) I could use the "add printer wizard" but in Win10 no printer(s) are found
So I had to manually add a TCP/IP printer port (which of course is easily done)]
The Win7 or Win 8 drivers seem to work nicely on Windows 10 (but I use the generic drivers only)
I personally don't think that finding a printer by Windows (that found the same printer in Win7 and Win8) can be blamed on HP
In the early days, installing a (network) printer was way more difficult than it is nowadays.
I am pretty sure this issue with not finding Network Printers will be solved soon
Just to chime in: I think this is a combination of idiosyncratic driver writing by HP (I have now come across the problem twice that for a wireless printer although installed and connected to the network the driver installation programme refuses to install the drivers on a second or third PC unless that PC is connected to the printer via usb first). Now, with win10, the OS sees the printer, reports it as "ready" and then as soon as I press print, there's a printer error with no indication as to what the problem actually is. Resetting the printer does not work, so I guess I'll reinstall the drivers (if they let me...)
That is what happened to me. Windows showed the printer as ready but as soon as you sent something it just said "error" and nothing happened. And of course, no explanation of that error meaning. Running the troubleshooter did nothing either.