Some configurations of the w32time Service (NTP)

In the XP system, to set the local host as a time server, in addition to setting enabled 1 under HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ timeproviders \ ntpserver, you also need to set announceflags in HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ config to 10 (decimal, hexadecimal ).
If we enable the "time and date" settings in the Windows operating system, we can see that the "Internet time" tab is displayed, we can set the automatic synchronization time from the system to the specified NTP server. However, in the XP system, the time interval for each synchronization is 7 days, and Vista is 60 hours; the synchronization frequency is too slow for a computer that has a problem with a motherboard such as my laptop and is totally out of order in a day. So I want to shorten the synchronization interval, however, this value is not visible in the "Configure Internet time settings" area; so I have to change the Registry. I looked for it, but it is not very hidden, there is a specialpollinterval under HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ w32time \ timeproviders \ ntpclient. You can modify this value, for example, I changed it to 300 (unit: Second, decimal, the hexadecimal format is 12c), that is, synchronization once every 5 minutes. My computer looks normal at last.
PS: If your firewall blocks the synchronization time and you do not dare to turn off the firewall, add a rule. The internal and external port numbers of the NTP service are both 123 (This number ), the protocol type is UDP. This setting is also valid for ntpserver and ntpclient.