Possible troubleshooting may proceed as follows:
- Firewall or port filter is blocking NTP packages.
- Make sure that firewall settings in Windows enable UDP protocol in both ways (inbound/outbound) on port 123.
- Some w32time versions coming with Windows XP or Windows Server 2003 may be unable to query the time from NTP servers.
- A workaround for the recognized problem is to change the behaviour of the w32time.