After you install Exchange 2007 on a computer, you can add server roles that are not yet installed on that computer. The Client Access, Hub Transport, Mailbox, and Unified Messaging server roles can coexist on the same computer in any combination. You cannot add the Edge Transport server role to a computer that has any of the other server roles installed.

For detailed steps about how to add a server role, see How to Modify an Exchange Installation.

If you remove a server role from an Exchange 2007 server, Exchange is still installed on that server.

For detailed steps about how to remove a server role, see How to Remove Exchange 2007 Server Roles.

Note:
If you remove all server roles and you remove the Exchange Management Tools, you will completely remove Exchange from the server. This includes the removal of all server roles, all installation files, and the Exchange server object for this server and all its child objects from the Active Directory directory service.

If you remove Exchange 2007 from a server, the following are removed:

• All server roles
  
  
• All installation files
  
  
• The Exchange server object and all its child objects from Active Directory
  
  

Removing Exchange from a server does not remove the database or log files. You must remove those files manually.

For detailed steps about how to remove Exchange Server 2007, see How to Completely Remove Exchange 2007 from a Server.

If you remove an Exchange 2007 organization, you remove Exchange 2007 from each server in the organization. You also remove all the Exchange security groups and the Exchange configuration object from Active Directory.

For detailed steps about how to remove an Exchange Server 2007 organization, see How to Remove an Exchange 2007 Organization.

To remove servers from a coexistence scenario with Exchange 2007 and either Exchange 2003 or Exchange 2000, you must perform additional steps so that all features and functionality will continue to work as expected.

When you remove the last Exchange 2003 or Exchange 2000 server from an Exchange organization that is running Exchange 2007, you must perform the following steps:

• Move all public folder replicas to an Exchange 2007 server.
  
  
• Move the offline address book (OAB) generation process to an Exchange 2007 server.
  
  
• Move public folder and mailbox stores to an Exchange 2007 server.
  
  
• Move the public folder hierarchy.
  
  
• Replace any outbound SMTP connectors on the Exchange 2003 or Exchange 2000 server with Exchange 2007 send connectors.
  
  
• Verify that inbound mail is routed to an Exchange 2007 server.
  
  
• Verify that inbound protocol services point to an Exchange 2007 server.
  
  
• Remove the routing group connector between the Exchange 2007 routing group and the Exchange 2003 or Exchange 2000 server.
  
  
• Remove any Mailbox Manager recipient policies on the Exchange 2003 or Exchange 2000 server.
  
  
• Delete the Recipient Update Service.
  
  

For detailed steps about how to remove the last Exchange 2003 or Exchange 2000 server from an Exchange organization that is running Exchange 2007, see How to Remove the Last Legacy Exchange Server from an Organization.

When you remove the first Exchange 2007 server that you installed in an Exchange organization with Exchange 2007 and either Exchange 2003 or Exchange 2000, you must do the following:

• Move public folder replicas from the first Exchange 2007 server, which you will remove, to another Exchange 2007 server.
  
  
• Modify routing group connectors, Send connectors, and Foreign connectors so that the Exchange 2007 server that you will remove is no longer the source server or target server for the connectors.
  
  

For detailed steps about how to remove the first Exchange 2007 server that you installed, see How to Remove the First Exchange 2007 Server in a Coexistence Scenario.

To move an Exchange 2007 server to a new computer and keep the same server name, you must perform specific steps for each server role. For detailed steps, see Moving Exchange Servers to New Hardware and Keeping the Same Server Name.

It is not supported to move an Exchange 2007 server from one domain to another domain. Additionally, it is not supported to run the setup /mode:recoverserver command against an Exchange computer object that previously existed in a different domain. If you must move an Exchange 2007 server to another domain, you must instead perform one of the following tasks:

• If you want to move an Exchange server between domains within the same forest in a planned scenario (for example, due to a reorganization), we recommend that you install new servers in the new domain. You can then move the mailboxes from the server in the old domain to the server in the new domain. You can also replicate public folder content to the new server. For more information about how to move mailboxes in Exchange 2007, see How to Move a Mailbox Within a Single Forest. For more information about replicating public folder content, see Managing Public Folder Replication.
  
  
• If you want to move an Exchange server between domains due to an unplanned failure or disaster, we recommend that you restore the Exchange 2007 databases and mailboxes to a new Exchange server that you install in the new domain. To move the current Exchange information to the new Exchange server, you must have a good backup copy of the databases that were on the failed server. For more information about restoring a database to a new server, see How to Restore a Mailbox Database to a New Server with Database Portability.
  
  

  Note:

  If you have removed the server object of the failed Exchange server from Active Directory, when you install the new server, you can use the same server name in the new domain. When you install Exchange 2007, make sure that you join the same administrative group of which the old server was a member. For more information about removing the server object of the failed Exchange server, see Microsoft Knowledge Base article 278918, How to manually remove a single Exchange-based server from Active Directory.