Increasing the accuracy of windows 2003 NTP time sync

Solution 1:

I'll agree with sysadmin1138 on the first 2 sentences in his answer:

That's not how NTP works, presuming a full NTP client. NTP works by disciplining the local clock so it can't fall out of sync, rather than hard-setting it back to true.

The rest, while true, is quite unnecessary.

All domain controllers are NTP servers by default. The DC which holds the "PDC Emulator" FSMO role should be configured to sync with an Internet NTP server, preferably a stratum 2 server. All other DCs will automagically sync themselves with that DC.

All domain members will automagically sync with their closest DC.

With the exception of the configuration of the PDC Emulator DC, all of this happens with no manual configuration required. There's really no need to mess with it under normal circumstances.

If you have non-Windows machines in your environment, you can simply configure them to use your AD domain name as an NTP server (assuming they are using the same DNS servers as your domain member machines), since the DNS A record for the AD domain name always resolves to all DC IP addresses.