Question : All Domain Users cannot connect to Exchange through the usual Outlook

After a DHCP Server Disaster which I repaired SOMEHOW by running a system state  and c drive recovery from back-up, I finally managed to get my users to connect to DCHP server again. After this they CAN connect to the net, ISA works fine BUT ALL USERS on the domain cannot connect to Exchange server with their installed outlook.

I checked the queue and all messages are being downloaded but are "stuck" when being delivered to the users store/mailbox. Also all Outlook (2003-2007) versions are reporting that they are disconnected, even after  user level restarts and server restarts. The only Error I see in the event log  is that the "mapi openmessagestore failed to initialize". After browsing the other EE users with the same issue about mapi I decided that the questions and answers really didnt pertain to me or my situation. What must I do to get all my users back connected to exchange?

Info

SBS 2003 Premium with all the bells and whistles
ISA
SQL
Exchange

All up to date with latest service packs and Microsoft updates.

FYI: I have ran the email repair wizard, maybe I missed something there?

This question is worth 1 BILLION points! lol ;-)

Cheers Experts,

Answer : All Domain Users cannot connect to Exchange through the usual Outlook

there is  no difference more or less. that function is supposed to be used by restricted user.
the only difference is not regarding ntfs permission, but the permission the programm will have on the system.
in vista and 7 allso running process have defined permission to write or modify registry. so a progra that run as administrator will have full access to the system.
in this way an administrator can choose wether to run a progrma with limited rights or with full permission.
hope this help.
paolo.