Can't connect to Exchange Server

Hi,

Wondering if anyone else has run into this. I'm running
Windows 2003 server and Exchange 2003. My Outlook 2000
clients all function flawlessly however when I installed
Office 2003 it says it cannot find the Exchange server. I
have tried both a clean install and a upgrade on two
separate clients with the same results. Any suggestions
would be greatly appreciated.

Thanks