Microsoft Windows has a built in time synchronisation facility called windows time (w32time.exe). Windows time is based on Network Time Protocol (NTP) an Internet protocol designed to synchronise computers on a network.

Using Windows Time service it is possible to configure the operating system to run as NTP time server, allowing you to synchronise all network devices to that time. Inn some older versions of Windows such Windows 2000 a stripped-down version of NTP called SNTP (Simplified Network Time Protocol) exists but is perfectly adequate for most timing applications.

Windows Time should be  present in the  service list. To locate Windows Time simply find the following subkey in the registry:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Time

NOTE: editing registry entries can cause irreversible problems it is strongly advised to create a backup before editing any entries to the registry.

Windows can easily set the system clock to use UTC (Coordinated Universal Time, the World's time standard) by accessing an Internet source (either: time.windows.com or time.nist.gov). To achieve this, a user merely has to double click the clock on their desktop and adjust the settings in the Internet Time tab.

It must be noted however, that Microsoft and other operating system manufacturers strongly advise that external timing references should be used as Internet sources can't be authenticated.

To configure the Windows Time service to use an external time source, click Start, Run and type regedit then click OK.

Locate the following subkey:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParametersType

In the right pane, right-click Type then click Modify, in edit Value type NTP in the Value data box then click OK.


Locate the following subkey:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeConfigAnnounceFlags.

In the right pane, right-click AnnounceFlags and click Modify. The ‘AnnounceFlags' registry entry indicates whether the server is a trusted time reference, 5 indicates a trusted source so in the Edit DWORD Value box, under Value Data, type 5, then click OK.

Network Time Protocol (NTP) is an Internet protocol used for the transfer of accurate time, providing time information along so that a precise time can be obtained

To enable the Network Time Protocol; NTPserver, locate and click:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpServer

In the right pane, right-click Enabled, then click Modify.

In the Edit DWord Value box, type 1 under Value data, then click OK.

Now go back and click on

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParametersNtpServer

In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type the Domain Name System (DNS), each DNS must be unique and you must append 0x1 to the end of each DNS name otherwise changes will not take effect.

Now click Ok.

Locate and click the following

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpClientSpecialPollInterval

In the right pane, right-click SpecialPollInterval, then click Modify.

In the Edit DWORD Value box, under Value Data, type the number of seconds you want for each poll, ie 900 will poll every 15 minutes, then click OK.

To configure the time correction settings, locate:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig

In the right pane, right-click MaxPosPhaseCorrection, then Modify, in the Edit DWORD Value box, under Base, click Decimal, under Value Data, type a time in seconds such as 3600 (an hour) then click OK.

Now go back and click:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig

In the right pane, right-click MaxNegPhaseCorrection, then Modify.

In the Edit DWORD box under base, click Decimal, under value data type the time in seconds you want to poll such as 3600 (polls in one hour)

Exit Registry Editor

Now, to restart windows time service, click Start, Run (or alternatively use the command prompt facility) and type:

net stop w32time && net start w32time

And that's it your time server should be now up and running.