said by Daniel :

It is my understanding that you can break bindings on the external adapter while keeping them intact on the internal one. This warrants more testing, however, as I haven't done this in quite some time.

Thanks for the comment; I'll definitely confirm this.

said by TheWiseGuy :

I could be wrong but I believe he is correct, that on a Win9x or before box, it is impossible to only bind NetBios to the Internal Adapter, that on a Win9x box it is all or nothing.

said by Daniel :

Steve Gibson's site, while quite informative, sensationalize the risk to systems in a big way. All one needed to do to keep from sharing files over the Internet is unbind File and Print sharing from the TCP/IP protocol within network properties for the adapter that faces the outside. This could be done while leaving the binding intact for the internal adapter(s) so that you could benefit from file sharing on the internal, trusted network while having it disabled for the untrusted one(s).

said by Steve Gibson:

After a reboot, the information-leaking port 139 will finally be closed . . . but ONLY IF every service is unbound from every instance of the TCP/IP protocol. If ANY one of the services remains bound to ANY instance of the TCP/IP protocol (i.e. TCP/IP for ANY adapter), then unsafe NetBIOS services will be available for ALL hardware adapters!