Editing Windows Operating System (section)

== Synchronize with external time source ==

Steps originated from: [http://www.windowsnetworking.com/articles_tutorials/Configuring-Windows-Time-Service.html Configuring the Windows Time Service]

Go to registry editor by typing <code>regedit.exe</code> in run box.

Edit:

'''HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\Type'''

Change this REG_SZ value from NT5DS to NTP

Edit:

''' HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags'''

This registry entry controls whether the local computer is marked as a reliable time server (which is only possible if the previous registry entry is set to NTP). Change the decimal REG_DWORD value from 10 to 5 here.

'''HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer'''

This registry entry specifies a space-delimited list of stratum 1 time servers from which the local computer can obtain reliable time stamps. The list may consist of one or more DNS names or IP addresses (if DNS names are used then you must append ,0x1 to the end of each DNS name). For example, to synchronize the PDC Emulator in your forest root domain with tock.usno.navy.mil, an open-access SNTP time server run by the United States Naval Observatory, change the value of the NtpServer registry entry from time.windows.com,0x1 to tock.usno.navy.mil,0x1 here. Alternatively, you can specify the IP address of this time server, which is 192.5.41.209 instead.

List of open NTP servers [http://tycho.usno.navy.mil/ntp.html USNO NTP NETWORK TIME SERVERS]

Now stop and restart the Windows Time service using the following commands:

'''net stop w32time'''

'''net start w32time'''

It may take an hour or so for the PDC Emulator to fully synchronize with the external time server because of the nature of the polling method W32Time uses. Depending on the latency of your Internet connection, the accuracy of the CMOS clock on your forest root PDC Emulator may be within a second or two of UTC. If you need more accurate time however, you can purchase a hardware time source like an atomic clock and connect it to your PDC emulator.

Alternatively, if you don’t want to wait for time convergence to occur between your stratum 2 time server (your forest root PDC Emulator) and the external stratum 1 time server, you can run the following command on your PDC Emulator:

<code>w32tm /resync /rediscover</code>