Windows XP NTP Time Server

Windows XP has an integrated time synchronisation service, installed by default, that can synchronise to a NTP Time Server. Indeed, by manipulating registry settings for the service it can act as both an SNTP client and server to synchronise other network clients.

The 'Windows Time' service should be present in the systems service list. The application executable is 'w32time.exe'. The parameter list for w32time can be found in the registry at:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time

To configure a Windows XP machine to synchronise to an external NTP server, edit the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\Type

Set value to NTP.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags

Set the value to 5 for reliable time source

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NTPClient\SpecialPollInterval

Set this to the period in seconds that the Windows XP machine should poll the NTP server. A recommended value is 900 seconds which equates to every 15 minutes.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NTPServer\Enabled

Change this value to 1.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer

Provide a list of IP address or DNS names, separated by a space, of time server that the Windows XP machine can synchronise to.