Time server

I am currently updating pcs from xp to windows 7. With xp and client 4.91 the pc automatically gets the time from the netware server. With windows 7 and client 2 it does not sync the time. How do I get the time from the netware server to the pc. I know I can use the internet time in windows but I would prefer to use an internal server as my netware server already polls an external source