Share via


Event ID 21 — Local Time Synchronization

Applies To: Windows Server 2008

The Windows Time service (W32time) synchronizes local time with a time source. The Windows Time service on a domain controller can be configured as either a reliable or an unreliable time source. The Windows Time service running on a client will attempt to synchronize its time source with servers that are indicated as being reliable. The Windows Time service can configure a domain controller within its domain as a reliable time source, and it synchronizes itself periodically with this source.

Event Details

Product: Windows Operating System
ID: 21
Source: Microsoft-Windows-Time-Service
Version: 6.0
Symbolic Name: MSG_NO_INPUT_PROVIDERS_STARTED
Message: The time service is configured to use one or more input providers, however, none of the input providers are available. The time service has no source of accurate time.

Resolve

Configure one or more reliable input providers

The configuration of the time source (also known as the time provider) is not valid, or the time source is no longer accessible. Check the time source configuration, and configure a different time source, if necessary. Perform the following procedure on the computer that is logging the event to be resolved.

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To configure a different time source:

  1. Open a command prompt as an administrator. To open a command prompt as an administrator, click Start. In Start Search, type Command Prompt. At the top of the Start menu, right-click Command Prompt, and then click Run as administrator. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  2. To verify that the time source name or address is correct, at the command prompt, type w32tm /query /source, and then press ENTER. If the name is not correct, enter a valid time source name or address. If the name is correct, check for network connectivity issues, and then verify that the time source is functioning correctly.
  3. To configure a new time source, at the command prompt, type w32tm /config, and then press ENTER. For complete command syntax, at the command prompt, type w32tm /?, and then press ENTER.

Verify

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To verify that the Windows Time service is synchronizing correctly:

  1. Open a command prompt as an administrator. To open a command prompt as an administrator, click Start. In Start Search, type Command Prompt. At the top of the Start menu, right-click Command Prompt, and then click Run as administrator. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  2. At the command prompt, type W32TM /resync, and then press ENTER.
  3. At the command prompt, type W32TM /query /status, and then press ENTER. The command displays the status of the Windows Time service synchronization. The Last Successful Sync Time line of the output displays the date and time that you ran the W32TM /resync command in the previous step. Also, check the computer name that is shown as the Source. This should be the name of a domain controller (or administrator-configured time server).

To confirm that the Windows Time service was synchronized successfully with its time source when you ran the W32TM /resync command, verify that Event ID 35 appears in the Event Viewer.

For more information about the Windows Time service, see Windows Time Service Technical Reference (https://go.microsoft.com/fwlink/?LinkID=25393).

Local Time Synchronization

Active Directory