[ntp:questions] Re: disabling the time daemon in winNT

John Howells John.Howells at marconi.com
Wed Aug 27 09:00:05 UTC 2003

Drk Ryan wrote:
> From the MS knowledge-base:
> With WinNT the kernel calls the time daemon to run approximately every
> hour. If the system time and the time maintained by the RTC drift
> apart by more than one minute, then the system time is re-synchronised
> to the RTC time.
> http://support.microsoft.com/?kbid=232488
> Does this have to be disabled before starting ntpd?
> Is it simply a case of disabling W32Time in the Services menu?
> I think a similar situation also exists in Solaris.

The MS document you quote does note that "If you use a time
synchronizing service, such as the TimeServ.exe tool included with the
Windows NT 4.0 Resource Kit, the tool updates the time in Windows and
the computer's RTC." Although not explicitly stated, my understanding is
that calling the WinNT time management functions restarts the one hour
timer referred to, so as long as NTP is running it should never mature.

The Windows Time Service (aka W32Time) only came in with Windows 2000,
and that should be disabled when another time service is being used. If
it is running and can find an appropriate server it will try and set the
time independent of what the NTP software is doing. This can result in
the clock being periodically changed in ways that cause the NTP software
great puzzlement, as previous messages here have shown.

John Howells

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