How to Configure NTP Server Using Regedit

Configuring custom Network Time Protocol (NTP) synchronization targets allows administrators to ensure that Windows systems maintain accurate time against specific, reliable internal or external time sources. This guide explains how to define custom NTP servers and configure the Windows Time service (W32Time) directly through the Windows Registry Editor (regedit).

Step 1: Open the Registry Editor

  1. Press Win + R on your keyboard to open the Run dialog.
  2. Type regedit and press Enter (or click OK).
  3. Confirm the User Account Control (UAC) prompt if prompted.

Step 2: Navigate to the Parameters Key

In the Registry Editor, navigate to the following path using the left sidebar:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters

Step 3: Configure the NTP Server List

  1. Locate the string value named NtpServer in the right pane.
  2. Double-click NtpServer to open its properties.
  3. In the Value data field, enter your custom NTP server addresses separated by spaces. Append the appropriate configuration flag (typically ,0x9 for client mode and fallback) to each server entry.
    • Example: time.google.com,0x9 pool.ntp.org,0x9 192.168.1.100,0x9
  4. Click OK to save the changes.

Common flag values: * ,0x1 – SpecialInterval * ,0x2 – UseAsFallbackOnly * ,0x4 – SymmActive * ,0x8 – Client * ,0x9 – Client + SpecialInterval (recommended for standard domain and standalone clients)

Step 4: Set the Synchronization Type

  1. In the same Parameters key, locate the string value named Type.
  2. Double-click Type and set the Value data to one of the following:
    • NTP: Synchronizes strictly with the servers specified in the NtpServer list.
    • AllSync: Synchronizes with both domain hierarchy and specified NTP servers.
    • NoSync: Disables time synchronization.
  3. For standalone custom NTP targets, set the value to NTP and click OK.

Step 5: Enable the NTP Client Provider

  1. Navigate to the following subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpClient
  2. Locate the DWORD (32-bit) Value named Enabled.
  3. Double-click it and ensure the Value data is set to 1. Click OK.

Step 6: Restart the Windows Time Service

For the registry changes to take effect, the Windows Time service must be restarted:

  1. Open Command Prompt as an Administrator.
  2. Run the following commands sequentially:
net stop w32time
net start w32time
w32tm /resync /force

Step 7: Verify Synchronization Status

To verify that the system is successfully synchronizing with your configured targets, run:

w32tm /query /status

Check the Source line in the output to confirm that it reflects the custom NTP server specified in your registry configuration.