Windows 2008 R2 - Synchronize time with external NTP server

1. On PDC server , stop the W32Time service , run command prompt as administrator, type net stop w32time

2. Configure the external time source, type w32tm /config /syncfromflags:manual /manualpeerlist:"net server"

    Example: w32tm /config /syncfromflags:manual /manualpeerlist:"my.pool.ntp.org"

3. Make PDC a reliable time source for the client, type w32tm /config /reliable:yes

4. On PDC server , start the W32Time service, type net start w32time

5. To check the status of your current time server settings, type w32tm /query /status

6. To display the configuration of run-time and where the setting come from, type w32tm /query /configuration

http://technet.microsoft.com/en-us/library/cc773263(WS.10).aspx

http://technet.microsoft.com/en-us/library/cc784553(v=ws.10).aspx