Annoying NetBios!

How could I send a message to an IP, which I have banned by means of my firewall because it is constantly attempting unsolicited access to my UDP 137 Port and S. Ports 1035 ? 1039 (NetBios name)? It is annoying! I have Windows 98 well updated, CableModem Broadband (LAN) and McAfee Firewall and VirusScan Online (Security Center). Moreover, is there some way to block NetBios without losing my Internet ability and features of LAN?s? Thanks from Chile, the Finis Terrae!