Thank you both, gentlemen. As you both suggested, despite the fact that File and printer sharing was selected, there were no shared resources for GIRLS to see. Selected C drive, and changed properties to allow sharing and lo and behold, network problem solved!
Alas, still no joy with ICS. General Electric, ICS set up wizard makes it fairly clear that it should be allowed to select an IP address automatically, which is what I have always had selected, but I gave your numbers a go on both computers. Neither computer could access the internet at all, so I've gone back to automatic selection of addresses.
Now I'm off to investigate the URL's you both kindly supplied me with. Will advise further.
Should Logon for Microsoft Network be selected on
both computers, or just the host?