Well, for me anyways (Leopard 10.5.7). It was driving me nuts as to why when I browsed the network my windows machines were not showing up. I then fired up my Server 2003 test machine in vmware and osx found it right away. This got me thinking... (dangerous!)

I jumped into the terminal and did the following:

sudo -s
<your password>

cd /var/db
nano smb.conf

find the line that says:

wins support = no

change it to yes

Control X, and press enter

then enter the following commands

service smbd stop
service nmbd stop
service smbd start
service nmbd start

exit and exit again

Now go to your Finder-Go-Network

And you PC machines should be there.

Amazing post. I followed the steps and those worked quite good. So much helpful information. So much thank you for sharing such useful thing.