Windows support the Network Time Protocol (NTP).

This article gives you the steps you must take in order to make your client pickup the time from the network and set your local clock.

net time /setsntp:myhostname
net stop w32time
net start w32time

Where myhostname is the name of your NTP server.

C:\Documents and Settings\mrn>net time
Current time at \\MYHOSTNAME is 11/4/2009 1:13 PM

The command completed successfully.

You can find more goodies relating to the registry settings here.