How to synchronize the time with the Windows Time service in Windows XP (307897)

SUMMARY

This article describes how to synchronize the time on your computers by using the Windows Time Service.

In Microsoft Windows XP, the Windows Time service automatically synchronizes your computer's internal clock with other clocks in the network. The time source for this synchronization varies, depending on whether the computer is joined to an Active Directory domain or to a workgroup.

When the computers are part of a workgroup, you must manually configure the time synchronization settings. You might identify a computer as a locally reliable time source by configuring the Windows Time service on that computer to use a known accurate time source, either by using special hardware or by using a time source that is available on the Internet. You can configure all other workgroup computers manually to synchronize their time with this local time source.

If the computers belong to an Active Directory domain, the Windows Time service configures itself automatically by using the Windows Time service that is available on domain controllers. The Windows Time service configures a domain controller in its domain as a reliable time source and synchronizes itself periodically with this source. You can modify or overwrite these settings, depending on your specific needs.

How to synchronize the time on a member computer in an Active Directory domain

1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2. Type w32tm /resync, and then press ENTER.

How to synchronize an internal time server with an external source

1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2. Type the following line, where peerlist is a comma-separated list of Domain Name System (DNS) names or IP addresses of the appropriate time sources, and then press ENTER:

   w32tm /config /syncfromflags:manual /manualpeerlist:peerlist

3. Type w32tm /config /update, and then press ENTER.

Notes

• The most common use of this procedure is to synchronize the internal network's authoritative time source with a very precise external time source. However, you can run this procedure on any Windows XP-based computer.
• If the computer cannot reach the servers, the procedure does not succeed and an entry is written to the Event log.
• You can use computers on the Internet to provide accurate time information. For example, use the National Institute of Standards and Technology (NIST), which provides the NIST Network Time service.

How to configure services

How to start, stop, pause, resume, or restart a service

Note You must be logged on as an administrator or a member of the Administrators group to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure.

1. Click Start, click Control Panel, click Performance and Maintenance, click Administrative Tools, and then double-click Services.
2. In the Details pane, click the service.
3. On the Action menu, click Start, Stop, Pause, Resume, or Restart.
4. To configure the startup parameters for a service, right-click the service, click Properties, and then type the parameters in the Start parameters box before you click Start. These settings are used only once and are not saved. A backslash character (\) is treated as an escape character; type two backslashes for each backslash in a parameter.

Notes

• If you stop, start, or restart a service, any dependent services are also affected.
• Changing the default service settings might prevent key services from running correctly. Use caution when you change the Startup Type and Log On As settings for services that are configured to start automatically.

How to configure how a service is started

Note You must be logged on as an administrator or a member of the Administrators group to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure.

1. Click Start, click Control Panel, click Performance and Maintenance, click Administrative Tools, and then double-click Services.
2. Right-click the service that you want to configure, and then click Properties.
3. Click the General tab, and then in the Startup type box, click Automatic, Manual, or Disabled.
4. To specify the user account that the service can use to log on, click the Log On tab, and then use one of the following methods:
   • To specify that the service use the LocalSystem account, click Local System account.
   • To specify that the service use the LocalService account, click This account, and then type NT AUTHORITY\LocalService.
   • To specify that the service use the NetworkService account, click This account, and then type NT AUTHORITY\NetworkService.
   • To specify another account, click This account, click Browse, and then specify a user account in the Select User dialog box. When you are finished, click OK.
5. Type the password for the user account in the Password box and in the Confirm password box, and then click OK.

Notes

• Changing the default service settings might prevent key services from running correctly. Use caution when you change the Startup Type and Log On As settings for services that are configured to start automatically.
• If you enable or disable a service and you encounter a problem in starting the computer, you might be able to start the computer in Safe mode. You can then change the service configuration or restore the default configuration.
• If you select the Allow service to interact with desktop check box, the service is configured to provide a user interface on a desktop. This feature is available only if you click Local System account and only if the service is configured to interact with the desktop.

Troubleshooting

Clients not synchronized with servers can occur if the Windows Time service has been stopped manually. To resolve this issue, start the Windows Time service.

To start the Windows Time service:

1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2. Type net start w32time, and then press ENTER.