1. The command works once you have Samba installed and configured on Linux. Do you have it installed and configured?
2. The windoze computers need networking configured. You should have all the code installed. Have a look at this document to see how to configure various flavors of windoze.
http://us1.samba.org/samba/docs/using_samba/toc.html
Chapter 3 and 5 cover it all.
3. There is a program called LinNeighboroughood that can "scan" the network. It will report the configured windows boxes.