Our AD is windows 2003 r2 SP2 (32bit) I am thinking how can I do schema update for exchange 2010. The DVD is 64 bit Any 32 bit version

It doesn't matter if your DC are 32-bit or not. You have to run the schema update from a 2008 (or R2) 64-bit server in the same AD site as the schema master. Most people do it from the server that they are going to install Exchange on since it will meet those requirements anyway. http://technet.microsoft.com/en-us/library/bb125224.aspx Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

In the technet, it said In each domain in which you install Exchange 2010, you must have at least one domain controller running any of the following: Windows Server 2003 Standard Edition with Service Pack 1 (SP1) or later (32-bit or 64-bit) Windows Server 2003 Enterprise Edition with SP1 or later (32-bit or 64-bit) Windows Server 2008 Standard or Enterprise (32-bit or 64-bit) Windows Server 2008 R2 Standard or Enterprise Therefore, I think it is not necessary to run schema update from a 2008 (or R2) 64-bit server. Ok, let say it is necessary, It means I have to build a 64 bit Windows 2008 DC first? or just a member server

What you quoted is what DC can be in place. Your domain controllers can be 32-bit or 64-bit 2003+. The server that you run the schema update from must be 64-bit. From link: in the setup /PrepareSchema section "You must run this command on a 64-bit computer in the same domain and in the same Active Directory site as the schema master" From my experience it doesn't work from a 2003 64-bit server. This server does not have to be a DC, it can be any member server that is 64-bit in the same AD site as the schema master.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

Because Exchange 2010 have to runing on 64bit, and will be a member server. So, I can run the schema update in that server, am i correct?

that is correct...as long as the server that you are going to install Exchange on is in the same AD site as the schema master. If not put in that AD site to do the schema updates and then move it where you want.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com