Your network contains an Active Directory forest. The forest contains one domain named
contoso.com.
You discover the following event in the Event log of client computers: “The time provider
NtpClient was unable to find a domain controller to use as a time source. NtpClient will try
again in %1 minutes.”
You need to ensure that the client computers can synchronize their clocks properly.
What should you do?

A.
Move the domain naming master role.

B.
Restart Active Directory Domain Services (AD DS) service.

C.
Move the PDC emulator role.

D.
Move the infrastructure master role.

E.
Move the global catalog server.

F.
Move the RID master role.

G.
Move the bridgehead server.

H.
Move the schema master role.

I.
Deploy an additional global catalog server.

J.
Install a read-only domain controller (RODC).

Explanation:
It could be that the server holding the PDC Emulator role has failed. Whatever the cause, we
need to move the PDC Emulator role to another domain controller to restore time
synchronization in the domain.
Reference 1)
http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Windows+Operatin
g+System&ProdVer=5.2&EvtID=14&EvtSrc=w32time&LCID=1033
Event ID
Message
The time provider NtpClient was unable to find a domain controller to use as a time source.
NtpClient will try again in %1 minutes.

Windows Time Service is configured to use the domain hierarchy to locate its time source. It
could not locate a domain controller that is a suitable time source. The time service will
continue to search for an acceptable domain controller. If the time service cannot locate a
time source after the maximum number of attempts, the Win32Time 49 message will be
logged.
Reference 2)
MS Press – Self-Paced Training Kit (Exam 70-640) (2nd Edition, July 2012) page 531
PDC Emulator Role
The PDC Emulator role performs multiple, crucial functions for a domain:
(…)
Provides a master time source for the domain – Active Directory, Kerberos, File Replication
Service
(FRS), and Distributed File System Replication (DFS-R) each rely on timestamps, so
synchronizing the time across all systems in a domain is crucial. The PDC emulator in the
forest root domain is the time master for the entire forest, by default. The PDC emulator in
each domain synchronizes its time with the forest root PDC emulator. Other domain
controllers in the domain synchronize their clocks against that domain’s PDC emulator. All
other domain members synchronize their time with their preferred domain controller. This
hierarchical structure of time synchronization, all implemented through the Win32Time
service, ensures consistency of time. Coordinated Universal Time (UTC) is synchronized,
and the time displayed to users is adjusted based on the time zone setting of the computer.