DNS - Stale records and scavenge?
Records are normally automatically added to the zone when computers and domain controllers are added. In some cases, they are not automatically deleted. This are stale records.
Windows DNS server can "scavenge" this records.
Scavenging settings on a Resource Record
Goto DNS - click View -> Adcanced -> Klick on the properties of a record.
Scavenging Settings at the Zone
Klick on the properties of a zone and klick "aging".