>I downloaded the atomic clock and it synced the time through port UDP 13, but the problem is that my exchange server's time is still off. Is it a member of the domain? Try setting up manually to sync to your DC at a command prompt. "net time /setsntp:domaincontoller.domain.com" >I installed it on the domain controller, should it sync automatically or do I have to do it manually? You can set it to "ping" once per day. Also set it to auto start with Windows and to start minimized. You should point the domain controller to itself as a time server. Same command as above. Otherwise, you will see the time server error in the logs. John Tolmachoff MCSE, CSSA IT Manager, Network Engineer RelianceSoft, Inc. La Habra, CA 90631 www.reliancesoft.com