HKLM\SYSTEM\CurrentControlSet\Services\DNS\
The DNS\Zones subkey stores information about the authoritative zones of a DNS server. The Zones subkey contains subkeys that represent each of the authoritative zones on the server. (In this file, these subkeys are depicted as <Zone-name>.) The Zone-name subkeys store configuration data set separately for each authoritative zone.
In addition to the zone-name subkeys, if the DNS server is not root authoritative, the Zones subkey contains subkey named "." (period) which stores configuration data for the cache file, also known as the root hint file.