On a shared PC in my dietary department I have one user that can execute Outlook 2003 and access email without a problem. Second user receives unable to connect to exchange server. When accessing exchange configuration/address for non-working user the address is different, changes when they try to access emails even after correcting exchange server address.

Sounds like a bad Outlook Profile. Have you created a new Outlook profile? Otherwise you need to verify if the problem follows the user to another system. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources