My Win XP and Win 7 computers did not appear in windows explorer under networks.
I had the same issue as you with "Net View" and message "System Error 6118 has occurred".
I have searched a lot and applied a lot of advices found on the net.
Finally, I found the explanation for my configuration ( not sure that config of other persons is the same).

The main advice I can give to everyone : look in the eventviewer ( "administrative events" ).
This will spare you a lot of time !!
The reason was :
a PRINTER was blocking the computers from being master browser.
Message in eventviewer was "The name "WORKGROUP      :1d" could not be registered on the interface with IP address 192.168.1.13. The computer with the IP address 192.168.1.5 did not allow the name to be claimed by this computer."
Solution I applied (perhaps there are other solutions) : I set the printer to let it get its ip address from the dhcp ( ip dynamic address in place of static address ).  Another solution is probably to use another workgroup name than "workgroup".