We have created an Exchange 2008 environment and migrated all users and mailboxes from our Exchange 2003 environment to the Exchange 2008.  We started to uninstall Exchange 2003 from all the Exchange 2003 server and unjoin them from the domain.  All went well until the last Exchange 2003 server.  When I attempted to uninstall Exchange 2003, it encountered an error and began to rollback the uninstall process, and then a window stating a reboot was required.  After the reboot, the System Manager still shows the last server in the First Administrative Group, and MSE Mgmt and MSE System Attendant services started.  However, MS Exchange  no longer appears as a program installed in Control Panel "Add or Remove Programs".  How can I continue to uninstall Exchange 2003 from this server?  With Exchange 2008 already in our environment, is it save to reinstall Exchange 2003 in order to uninstall it?

Thanks for your help.

Hi,

From your description, I would like to verify your new Exchange server version, there is no Exchange 2008. What's more, if the old Exchange 2003 is not displayed in Control Panel's programs, you can recover it at first, and then uninstall it from Control Panel. It is the supported method.

Hope this can be helpful to you.

Best regards,