Looking for a NTP Server Software for Windows [closed]

I am using NetTime, from many years, both as client and server.

This software is primary a NTP client, but it works well also as NTP server within a LAN (option: allow other computer to sync to this computer).

We see far better than 500 ms from W32time, more like 16ms which is the resolution of the windows system timers. This is measured by real Linux stratum-2 NTPd servers on the same gigabit LAN. Google "windows time service tools and settings" and read about "updateinteval" setting, which can modified via group policy or directly in registry. Can't check right now, but I recall we have that set to 100 for all our servers, which is default for domain controllers but not other windows domain members.

Updated: We do in fact have this value set to 100 for all our servers. The UpdateInterval setting's details:

UpdateInterval

Registry path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config

Version: Windows XP, Windows Vista, Windows 7, Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, and Windows Server 2008 R2.

This entry specifies the number of clock ticks between phase correction adjustments. The default value for domain controllers is 100. The default value for domain members is 30,000. The default value for stand-alone clients and servers is 360,000.

As you can see, by default W32time only "steers" the clock once every 30,000 ticks for non-domain controllers, or far worse if they are not members of a domain. A tick on windows is usually 1/64 of a second depending on hardware, so that means the clock is only being adjusted once every 8 minutes or so in the default configuration. This is fine for most applications, but not fine for timing-sensitive applications.

More information can be found here: http://technet.microsoft.com/en-us/library/cc773263(v=ws.10).aspx#w2k3tr_times_tools_uhlp