I have a Server 2008 R2 box running Hyper-V, hosting VM's. I have 4 NIC's set up - the primary network NIC, 1 NIC for the SAN, and 2 NIC's for the virtual machines. The 2 NIC's for the virtual machines continue to register in DNS despite having the Register this Connection in DNS checkbox cleared. I am running a Windows Server 2003 Domain with AD-Integrated Zones.
Even after I delete the A records for the 2 NIC's for the virtual machines, they continue to re-appear in DNS.
I am not sure how to stop this behavior.
Your DHCP server may be configured to register them on their behalf.
http://technet.microsoft.com/en-us/library/ee941150%28WS.10%29.aspx
Palm to forehead. I rebooted the Server 08 box and the unwanted A records disappeared from DNS.
FYI, you could also just restart the DNS Client service instead of a full reboot.