http://tariqjaber.com/blog/2010/02/01/exchange-2010-on-windows-server-2008-r2-features-installation-and-transition-from-exchange-2003/

In this post I’ll start installing Exchange 2010 in an existing Exchange 2003 environment.

The order in which we must deploy Exchange 2010 server roles in an existing Exchange organization is as follow:
    -Client Access
    -Hub Transport
    -Unified Messaging (UM)
    -Mailbox Server

The first thing we should do is to change the Exchange organization to native mode. To change it we will use Exchange 2003 System Manager:
1.    Open Exchange System Manager.
2.    Right-click the organization and click Properties.
3.    In the General tab, under Change Operations Mode, click Change Mode. Click Yes to permanently switch the organization’s mode to native mode.

Legacy Host Names:

Now if you have Outlook Web Access (OWA) published and the users are accessing their mailboxes from outside the network, you have to use a legacy host name. A legacy host name is a name that will be assigned to Exchange 2003 OWA like legacy.domain.com, and the name that was being used for OWA, like mail.domain.com, will be assigned to the newly installed Exchange 2010. When the users connect to mail.domain.com, they will be redirected to Exchange 2003 front-end server and they will not be interrupted accessing their mailboxes using POP3, IMAP4 and Outlook Anywhere.

SSL Certificate:

Prepare your Exchange server 2010 certificate, it is better to have a Subject Alternative Names (SAN) certificate which contains the names of all Exchange 2010 and 2003 server’s names.

Preparing Active Directory for Exchange 2010 installation:

We need to prepare our Active Directory for Exchange 2010 installation. The account that we will use for the preparation should be member of the Schema Admins, Domain Admins and Enterprise Admins groups

1. Because we have an earlier version of Exchange 2003 installed, we must run
Setup.com /PrepareLegacyExchangePermissions or Setup.com /pl

On the server Mig-R2Ex14, which we have installed Exchange 2010 prerequisites on, I’ll run this command, run it as administrator:

The forest functional unit must be Windows Server 2003 native or later or you will got the error:

For more details about How to raise domain and forest functional levels in Windows Server 2003 see KB322692 and here for Windows Server 2008

2. Now we will prepare the schema using the command
Setup.com /PrepareSchema or Setup.com /ps

Wait for the replication to complete or force the replication.

For Exchange 2003, the schema version is 6903, you can check it using ADSIEdit.msc

After preparing the schema for Exchange 2010, the version will be 12640

3. After this, we will prepare Active Directory using the command
Setup.com /PrepareAd or Setup.com /p

Note in the command it says:
“Setup is going to prepare the organization for Exchange 2010 by using ‘Setup /PrepareAD’. No Exchange 2007 server roles have been detected in this topology. After this operation, you will not be able to install any Exchange 2007 server roles.”

4. Finally, we will prepare the domain
Setup.com /PrepareDomain or Setup.com /pd
If you want to prepare all the domains in your organization run the command
Setup.com /PrepareAllDomains or Setup.com /pad

Now we have prepared the domain, we are ready to start Exchange 2010 installation. I’ll talk about it in the next post.

References

Prepare Active Directory and Domains http://technet.microsoft.com/en-us/library/bb125224.aspx
Prepare Legacy Exchange Permissions http://technet.microsoft.com/en-us/library/aa997914.aspx

Our lab will consist of the following servers:

• Windows Server 2003 R2/SP2 Domain Controller with Exchange 2003/SP2 installed on the same box. Note that it is not recommended to have Exchange and Domain Controller on the same server but we are doing this for our test lab (http://technet.microsoft.com/en-us/library/aa997407(EXCHG.80).aspx).
• Additional Windows Server 2008 Domain Controller.
• One HUB/Client Access server roles installed on Windows Server 2008 R2.
• One Mailbox Server installed on Windows Server 2008 R2.

What is new in Exchange 2010

• Database Availability Group (DAG): This is the key feature in Exchange 2010 besides Incremental Deployment. DAG is a group of up to 16 Mailbox servers that host a set of databases and provide automatic database-level recovery from failures that affect individual servers or databases. Any server in a DAG can host a copy of a mailbox database from any other server in the DAG.
• Incremental deployment: In Exchange 2010, the cost and complexity of deploying and providing a high available site have been reduced. You don’t have to install Failover-Clustering as a pre-requisite to Exchange 2010. If you decide to use  DAG, you simply create one, and then add Mailbox servers to it. When you add a Mailbox server to a DAG, the Windows failover clustering feature will be automatically installed and a cluster will be created.
• Outlook Web Access (OWA) now supports Multiple browsers. If you are using Firefox or Safari, then you can use OWA as if you are using Internet Explorer.

And a lot of other features that I’ll talk about in other posts.

Installing Exchange 2010 prerequisites

Let’s start our lab. First of all we will install Exchange 2010 prerequisites.

• Microsoft Filter Pack: for the server that will host Mailbox or Hub Transport roles. Exchange Search uses IFilters to index text content in different file formats. Microsoft Filter Pack includes filters for Microsoft Office 2007 file formats. The following file name extensions are supported by the filter pack: .docm, .docx, .one, .pptm, .pptx, .vdx, .vsd, .vss, .vst, .vsx, .vtx, .xlsb, .xlsm, .xlsx, .zip. Visit 2007 Office System Converter: Microsoft Filter Pack .
  
• Open an elevated PowerShell Console and run the command:  
  Import-Module ServerManager
  
• In the same PowerShell console run the command :

  Add-WindowsFeature NET-Framework,RSAT-ADDS,Web-Server,Web-Basic-Auth,Web-Windows-Auth,Web-Metabase,Web-Net-Ext,Web-Lgcy-Mgmt-Console,WAS-Process-Model,RSAT-Web-Server,Web-ISAPI-Ext,Web-Digest-Auth,Web-Dyn-Compression,NET-HTTP-Activation,RPC-Over-HTTP-Proxy –Restart
   

• Because we will install Client Access Server role, after the system has restarted, log on as an administrator, open an elevated PowerShell console, and configure the Net.Tcp Port Sharing Service for Automatic startup by running the following command:
  Set-Service NetTcpPortSharing -StartupType Automatic
  

  Finally, make sure to always keep you servers updated