How to synchronize clocks for computers that are not online?

Question

I have some computers that run Windows 7 embedded and are connected to each other by a switch, but are not connected to a larger network or the internet. After a few weeks, the clocks drift and it is difficult to figure out what is going on in the logs between them. Is there a way to keep the clocks on these computers synchronized? Within 1 second would be good enough for my purposes.

I've searched for a solution and everything seems to link to or is a copy of this page: http://support.microsoft.com/kb/816042

One of the computers acts as a master for the others and I have configured it as described in the section "Configuring the Windows Time service to use an internal hardware clock" in the above article. I've attempted to configure another computer as described in the "Configuring the Windows Time service to use an external time source" section, using the IP address of the master for the NtpServer option. I waited 15 minutes and their clocks did not synchronize (they remain about 1 minute apart).

Also, is there a way to find error messages produced by the w32time service? Currently, my only approach is to change something and wait to see if it works.

These computers are not in a domain.

Solution

You will need to install a TimeServer on the same network. Now there are articles available to make a Windows 7 machine able to share time... but I am not sure. I know all Windows 2000+ Servers come with NTP enabled as standard and when you are in a domain it automatically uses the server's time across the domain.

Microsoft recommends using a dedicated time server, but that's like another machine.

There is however an option in the Group Policy Editor to enable the NTP server on Windows 7 - I found this... but nothing more.

Then each client needs its IP address for NTP changed to that machine, like [192.168.0.25].

But also, if you have a dedicated "server" (not really a server, just the main computer) machine, that holds all the data for example. You could run a virtual machine with a damn small Linux distribution and setting up an NTP on it is as easy as using the native installer. These distributions are minute and use almost no memory or CPU, but can do a lot of impressive things if you research it a bit.

But the best solution is to install a Windows Server and put all the machines in a domain.

You can try Windows SBS Essentials, and it's very cheap too.

Comments

[mccoyn]

It didn't work after a reboot. This link explains why: mcbsys.com/techblog/2010/09/…

[Piotr Kula]

Its just windows being a pain in the neck as usaull :( Sorry to hear that.. but that link explains hyper-v, in other words virutalization. You better of with using VM with a NTP server on it, that will auto start on reboot...

[mccoyn]

It also explains the service triggers. The virtualiztion stuff is just extra. To get it to work I had to run "sc triggerinfo w32time delete" since it is configured by default to not work if not on a domain. Yeah, windows being a pain.