Since I've upgraded to Leopard, I couldn't connect to my Windows network anymore. Browsing through various websites looking for answers, I tried pretty much all of them with no success. Not until I found this page. Is explanation is pretty simple and indeed makes my shared network show up once again!
Here's the explanation and instructions on how to fix it:
You have plenty of suggestions for fixing the Leopard Windows sharing issue, that I see are all a bit hit or miss. I think the reason for this is because a lot of the things people are trying are fixing the real root issue by accident.
The Leopard advanced network settings has a WINS tab, and in this there is a NETBIOS name field. This is auto-generated by Leopard - it looks like it uses the MAC address to generate it. However, if what is put in there is not compliant with the NETBIOS settings of the Windows network you are connected to, then browsing will not work, because the WINS server will not acknowledge the WINS requests coming from Leopard.
The actual NETBIOS name requirements supported vary depending on the flavour of OS running on the WINS servers on the network. I would suspect the best route to success is to use the most basic NETBIOS name requirements, back from the old Windows NT 4.0 days - stick in no more than an 8-character alphanumeric into the NETBIOS field, and all Windows browsing will be restored.
I had two Leopard machines, one which would browse and one which would not. The browsing one had an 8-character WINS setting, and the non- browsing one had a MAC address in the WINS field. Removing the MAC address and putting in a simple word in the WINS field IMMEDIATELY reinstated browsing.