Retired DNS server address shows up in registry

A few months back I retired an old DNS server, AD integrated, and replaced
with a newer machine..

On a somewhat regular schedule, the following registry key is updated with
the address of the old DNS server:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient

I have searched through all GPO's and cannot find any entry that is set to
the old DNS server address..

Can anyone point me to the item I need to modify to resolve this?

Thanks in advance,

Craig Lemke