Microsoft Windows [Version 6.0.6001] (C) Copyright 2006 Microsoft Corp. c:\windows>netsh interface ipv4 delete dnsserver ?
Usage: delete dnsserver [name=][[address=]|all]
name - The name of the interface where DNS servers are deleted.
address - One of the following values:: A specific IP address of a DNS server
you are deleting.
all: Deletes all configured IP addresses for DNS. servers.
Remarks: Deletes statically configured DNS server IP addresses for a
delete dnsserver "Local Area Connection" 10.0.0.1
delete dnsserver "Local Area Connection" all