For Windows 2000: Registry entries for the W32Time service
The following are important:
NtpServer : REG_SZ (optional)
Used to manually configure the time source. Set this to the DNS name or IP address of the NTP server to synchronize from. You can modify this from the command line by using the net time command. Value is blank by default.
Note If you enter multiple NTP entries you must separate the entries with a space. For example, if you enter two different IP addresses for two distinct NTP servers, you must separate the entries with a space. Do not use a comma to separate multiple IP addresses or multiple fully qualified domain names (FQDNs).
Period : REG_DWORD or REG_SZ
Used to control how often the time service synchronizes. If a string value is specified, it must be one of special ones listed below. If you specify the string value by using the numbers (65535 for example), then create the value as a REG_DWORD. If you use the word to specify the string value (BiDaily for example), then the entry should be created as a REG_SZ.
Type : REG_SZ
Used to control how a computer synchronizes.
The Nt5DS setting may not use a manual configured source.
NOTE: w32tm on XP is different to 2K versions.
Start and stop W32Time service - needed after a registry change:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\Parameters\ntpserver net time /setsntp:[:ntp|server list]