Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1986-2001 Microsoft Corp. C:\WINDOWS>netsh interface portproxy delete v4tov6 ?
Usage: delete v4tov6 [listenport=]|[[listenaddress=]|][[protocol=]tcp]
listenport - IPv4 port on which to listen.
listenaddress - IPv4 address on which to listen.
protocol - Protocol to use. Currently only TCP is supported.
Remarks: Deletes an entry to listen on for IPv4 and proxy connect to via IPv6.