The DNS Client service resolves and caches Domain Name System (DNS) names. If this service is stopped, a computer will not be able to resolve DNS names and locate Active Directory domain controllers.
A service can stop for many reasons, including:
The service was stopped by an Administrator.
The service encountered an exception that stopped the service.
The service was improperly configured, which prevented it from starting.
The service was prevented from starting because the user account assigned to the service could not be authenticated.
The service can be restarted using the Computer Management Console Task:
Start Computer Management Console