Share via

Upgrade to Exchange 2010

Applies to: Exchange Server 2010

Microsoft Exchange Server 2010 can be deployed in an Active Directory forest that has an existing messaging system. You have a coexistence scenario if the following conditions are true:

  • Exchange 2010 is deployed in an existing Exchange organization.
  • More than one Exchange version provides messaging services to the organization.

You can't upgrade an existing Exchange 2000 organization directly to Exchange 2010. You must first upgrade the Exchange 2000 organization to either an Exchange 2003 or Exchange 2007 organization, and then you can upgrade the Exchange 2003 or Exchange 2007 organization to Exchange 2010. We recommend that you upgrade your organization from Exchange 2000 to Exchange 2003, and then upgrade from Exchange 2003 to Exchange 2010. For more information about upgrading from Exchange 2000, see Planning an Upgrade from Exchange 2000 and Upgrading to Exchange 2007.

When an organization gradually transitions a messaging system from Exchange Server 2003 or Exchange 2007 to Exchange 2010, the organization will probably have to maintain more than one version of Exchange during that time.

The following table lists the scenarios in which coexistence between Exchange 2010 and earlier versions of Exchange are supported.

Coexistence of Exchange 2010 and earlier versions of Exchange Server

Exchange version Exchange organization coexistence

Exchange 2000 Server

Not supported

Exchange Server 2003


Exchange 2007


Mixed Exchange 2007 and Exchange Server 2003 organization


You can only deploy Exchange 2010 in an Exchange 2003 or Exchange 2007 organization that operates in native mode. You use Exchange System Manager to change the Exchange organization to native mode on an Exchange 2003 server or an Exchange 2007 server, as follows:

  1. Start Exchange System Manager. Click Start > Programs > Microsoft Exchange > System Manager.
  2. Right-click the organization, and then click Properties.
  3. Click the General tab, and then, under Change Operations Mode, click Change Mode. Click Yes if you are sure that you want to permanently switch the organization's mode to native mode.

The following topics in this section provide information about upgrading your organization to Exchange 2010: