Kb816042-official description of NTP configuration in Windows

1. Change the server type to NTP. To do this, follow these steps:
   1. Click Start, click Run, type regedit, and click OK ".
   2. Find and click the following registry subkeys:HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ Parameters \ type
   3. In the right pane, right-click "type" and click "modify ".
   4. In the edit Value Field, type NTP in the value data box, and click OK ".
2. Set announceflags to 5. To do this, follow these steps:
   1. Find and click the following registry subkeys:
      HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ config \ announceflags
   2. In the right pane, right-click announceflags and click Modify ".
   3. In the Edit DWORD Value Field, type 5 in the value data box, and click OK ".
3. Enable ntpserver. To do this, follow these steps:
   1. Find and click the following registry subkeys:
      HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ timeproviders \ ntpserver
   2. In the right pane, right-click enabled and click Modify ".
   3. In the Edit DWORD Value Field, type 1 in the value data box, and click OK ".
4. Specifies the time source. To do this, follow these steps:
   1. Find and click the following registry subkeys:
      HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ Parameters
   2. In the right pane, right-click ntpserver and then click Modify ".
   3. In the edit Value Field, TypePeersAnd then click OK ".

      Note::PeersIs a placeholder and should be replaced with the peer list (separated by spaces) from which your computer obtains the timestamp ). Each DNS name listed must be unique. Each DNS name must be appended with 0x1. If it is not appended after each DNS name, 0x1, the changes made in step 5 will not take effect.

5. Select the polling interval. To do this, follow these steps:
   1. Find and click the following registry subkeys:
      HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ timeproviders \ ntpclient \ specialpollinterval
   2. In the right pane, right-click specialpollinterval and click Modify ".
   3. In the "Edit DWORD Value" field, TypeTimeinsecondsAnd then click OK ".

      Note::TimeinsecondsIs a placeholder and should be replaced with the number of seconds between polling. The recommended value is 900 (decimal ). This value configures the time server to poll every 15 minutes.

6. Configure time calibration settings. To do this, follow these steps:
   1. Find and click the following registry subkeys:
      HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ config \ maxposphasecorrection
   2. In the right pane, right-click maxposphasecorrection and click Modify ".
   3. Click in the "base" box of "Edit DWORD Value" to select "decimal ".
   4. In the "Edit DWORD Value" field, TypeTimeinsecondsAnd then click OK ".

      Note::TimeinsecondsIs a placeholder and should be replaced with an appropriate value, such as 1 hour (3600) or 30 minutes (1800 ). The value you selected varies with the polling interval, network condition, and external time source.

   5. Find and click the following registry subitem:HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ config \ maxnegphasecorrection
   6. In the right pane, right-click "maxnegphasecorrection" and click "modify ".
   7. Click in the "base" box of "Edit DWORD Value" to select "decimal ".
   8. In the "Edit DWORD Value" field, TypeTimeinsecondsAnd then click OK ".

      Note::TimeinsecondsIs a placeholder and should be replaced with an appropriate value, such as 1 hour (3600) or 30 minutes (1800 ). The value you selected varies with the polling interval, network condition, and external time source.

7. Exit Registry Editor.
8. At the command prompt, type the following command to restart the Windows Time Service, and then press Enter: net stop w32time & Net start w32time

Http://support.microsoft.com/kb/816042