If you are having trouble getting File and Printer sharing to work and have multiple IP addresses from your ISP

The easiest way to fix this is to add the NetBeui or IPX/SPX protocol (make sure you enable NetBIOS over IPX/SPX) to all your computers and make sure it is bound to Client for Microsoft Networks and File and Printer Sharing for Microsoft Networks. This will set up File and Printer sharing independently from TCP/IP, so it won't matter what the TCP/IP settings are! Make sure you unbind these from TCP/IP.