I have a home network with two computers connected. It was
working fine sharing files and printers.
But then suddenly, when I opened "Entire Network" on one
of the computers, the window was empty (0 objects).  If I
search for a computer, the computer finds itself on the
network.  If I open the computer, I can go up a level to
the "Workgroup" and up a level to the "Entire Network".  
So the workgroup does exist, but I can't access it by
opening "My Network Places", "Entire Network".
Also, the other computer on my network doesn't show up in
that "Workgroup" or anywhere else on the network.  When I
search for a computer, the computer only finds itself, not
the other computer.
The other computer finds itself on the network by "My
Network Places", "Entire Network", "Workgroup".  It does
not find the other computer on the network.

Any ideas?  Thanks.