I have at last - after a month of frustration, found the solution to the network problem I described earlier in the thread. Guru Google strikes again
You may recall that on my home network my desktop computer can find both our laptops. The laptops can find each other, but neither could find the desktop.
The network advanced setting were all absolutely identical and the network trouble shooters found no problem.
But I just found this solution :-
Enable NetBIOS over TCP/IP
1. Hold Windows Key and Press R. Type ncpa.cpl and Click OK
2. Right-Click on the connection and choose Properties.
3. Click “Internet Protocol (TCP/IP) Version 4” in the list.
4. Click Properties, and then click Advanced.
5. On the Advanced TCP/IP settings windows, go to “WINS” tab.
6. Under NetBIOS setting, click “Enable NetBIOS over TCP/IP”, and then click OK.
Make a note of it - you never know when you might need it.