In order to configure a Windows 2008 R2 as NTP (Network Time Protocol) server we will need to do some changes in the machine Registry. Here we will specify how to modify both, for the server and for the client.

We will need at least to have one Windows 2008 R2 server acting as NTP server and one Windows 2008 R2 server acting as NTP client.

Server configuration:

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\TimeProviders\NTPServer]"Enabled"=DWORD:00000001

For the client configuration we will need to set it up as client and also set up the update interval:

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\TimeProviders\NTPClient]"Enabled"=DWORD:00000001"SpecialPollInterval"="600"

Establish NTP source, period and frequency:

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\Parameters]"NtpServer"="[IP address], 0x1""Type"="NTP""Period"="freq"

Side notes:

If the machine does not belong to an Active Directory, the service will not start. To make sure the service starts automatically, we need to run the following command:

sc triggerinfo w32time start/networkon stop/networkoff

To test NTP is correctly syncing:

w32tm /query /peers