How can I remove my last Exchange Server 5.5 installation from my Exchange Server 2003 organization?

Log on to the remaining Exchange 5.5 server and stop all services. The easiest way to do this is to stop the Exchange System Attendant by opening a command line and typing

net stop MSExchangeSA

You'll see a warning that this command will stop other services, click Yes. After the command finishes running, run the command again (which will now stop the actual MSExchangeSA service).

Log on to an Exchange 2003 server and start the Exchange 5.5 Administrator Console application (you must use the Exchange 5.5 version because Exchange 2003 tries to delete the Exchange server configuration from Active Directory--AD). Point the Exchange 5.5 Administrator Console to the Exchange 2003 server when prompted for a server.

Expand the , Configuration, Servers node and select the Exchange 5.5 server in the right pane of the Exchange administration application. From the Edit menu select Delete. The application performs a check for resources; click Yes to any resources still found (assuming you know you've migrated everything you require). You might also see a warning that the MSFB and MS extensions could not be loaded. Click Ignore, then click OK to delete the confirmation message.

Start the Exchange 2003 Exchange System Manager (ESM) and the Exchange 5.5 server will no longer be visible under the Servers container (, Administrative Groups, , Servers).

You can now delete the Site Replication Service connection by opening the Tools, Site Replication Services node. Select the "Microsoft Exchange Site Replication Service ()" and select Delete from the Edit menu. Click Yes to the confirmation message.

You can now raise the operational mode of the Exchange organization. Right-click the Exchange organization at the root of the node tree and select Properties. On the General tab click Change Mode, click Yes to the confirmation dialog box, then click OK to the main Properties dialog box

Now you can remove the Active Directory Connector (ADC) connections. Start the Microsoft Management Console (MMC) Active Directory Connector Services snap-in. Right-click each connection under the Active Directory Connector node and select Delete. You might receive a warning that the connection is the primary connection agreement (CA). Click OK and click Yes to the delete confirmation dialog box (You'll usually have at least two connections--one user and one public folder).

You can now uninstall the ADC tools and services from the server.