Exchange Server 2010 is available in two server editions: Standard Edition and Enterprise Edition. These are licensing editions that are defined by a product key. The release to manufacturing (RTM) and service pack 1 (SP1) versions of Exchange Server 2010 are now available. For more information, see Exchange 2010: Editions and Versions.

You have the following options for Exchange 2010 Setup:

Exchange Setup UI   Setup.exe is an interactive experience where you are guided by the Exchange 2010 Setup wizard.

Exchange Unattended Setup   Setup.com is an unattended experience where you provide command-line switches interactively or through a script. Setup.com is available from the Exchange 2010 DVD or the downloaded source files.

Setup for Exchange 2010 includes several installation modes:

Install   Use this mode when you're installing a new server role or adding a server role to an existing installation (maintenance mode). You can use this mode from both the Exchange Setup wizard and the unattended install.

Uninstall   Use this mode when you're removing the Exchange installation or removing a single server role from an existing installation (maintenance). You can use this mode from both the Exchange Setup wizard and the unattended install.

Upgrade   Select this mode used when you have an existing installation of Exchange and you're installing the new version. This mode is used for a Service Pack installation. You can use this mode from both the Exchange Setup wizard and the unattended install.

RecoverServer   Use this mode when there has been a catastrophic failure of a server, and you need to recover data. You must install a server using the same fully qualified domain name (FQDN) as the failed server, and then run Setup with the /m:RecoverServer switch. Don't specify the roles to restore. Setup detects the Exchange Server object in Active Directory and installs the corresponding files and configuration automatically. After you recover the server, you can restore databases and reconfigure any additional settings. To run in RecoverServer mode, you can't have Exchange installed on the server. The Exchange server object must exist in Active Directory. You can only use this mode during an unattended installation.

Note:
You must complete one mode of Setup before you can use another mode.

There have been several improvements to Setup in Exchange 2010 SP1:

• Failed Installations   Unlike Exchange 2010 RTM, Setup in Exchange 2010 SP1 now supports resuming a failed installation. (In Exchange 2010, if you have a failed installation, you can’t use the Uninstall mode to correct it.) A watermark in the registry identifies where Setup failed. You will not have to answer the Exchange 2010 Setup wizard questions again when you resume a failed Setup. You can resume the failed install, and let it succeed.
  
  
• Exchange Setup Log   Exchange SP1 improves the Exchange Setup Log by reducing the amount of non-essential information and correctly noting errors. The Setup Log is divided into discrete sections so it's easy to see where Setup failed. For more information, see Verify an Exchange 2010 Installation.
  
  
• Windows Roles and Features   Exchange 2010 SP1 adds the ability to install Windows roles and features that are required for your server roles.
  
  

For more information about these improvements, see New Deployment Functionality in Exchange 2010 SP1.