Seems to be lots more to this than meets the eye.
I've got one more PC on the LAN which I hope to
'test' my hypothesis on.
Yes, the printer s/ware needs to be installed on
each PC. But - so far - it seems important that
the first PC it's installed on, sets the printer as
NOT SHARED! And same for subsequent PCs.
Because, if set to SHARED AS . . . the Windoze
INSTALL PRINTER installation option on other PCs
on the LAN wants to connect to the "network"
printer as if it's a local printer (on the SHARED AS
PC), rather than use some sort of IP address or
the printer's LAN address as a default.
Interesting that once installed and showing up in
the printers folder, the printer does not show the
networked thingame as part of it's icon.
An HP tech told me that it is treated as a local
printer, despite being networked and despite my
seeming to discover that's OK, only
so long as
it's marked as NOT SHARED.
Curiouser and curiouser . . .
I'll be back with more on this saga . . . .