Hi gurus  Just needed to get a sanity check for process to upgrade my Exchange 2007 infrastructure to sp3. 1.) To the schemaprep and domain prep from the command line. Based on their being no Exchange 2007/Exchange 2003 servers this would be as follows: Setup /prepareschema Setup /prepareAD Do I need to put the Org name in here based on the fact that the Exchange org is already in place? Setup /preapredomain Once these schema updates have gone through to all my DCs my next question is the sequence in which servers should be upgraded: This is my plan thus far. 1.) I have a CAS/MBX?HT server which is where ActiveSync and Outlook Anywhere clients connect. 2.) I have a HT/CAS server in another site which is where the SMTP traffic enters the network. 3.) I have two other sites with a single CAS/HT/MBX Server. My upgrade process is as follows: 1.) Upgrade the Internet facing server listed in line 1 above first. 2.) Then upgrade the server listed on line 2 above. This is the SMTP gateway server. 3.) Then upgrade the two downstream servers to SP3. Have I missed anything here in my process? Any pointers would be appreciated as Ive been looking at this for a while and need some fresh eyes on it. Regards Peter Johnson

Hi Peter, You need to ensure that the internet facing CAS server updates first. main thumb rules are, Upgrade your computers in the following order: Client Access serversUnified Messaging serversHub Transport serversEdge Transport serversMailbox servers upgrade Client Access servers that reside on Internet-facing sites before you upgrade Client Access servers that reside on sites that do not have Internet connectivity. below may also help you when you do the SP3 upgrade, Upgrade Prerequisites Warnings/Errors - Exchange 2007 SP3 I recently did an upgrade from exchange 2007 sp1 to SP3 without any issues.... Praveen Balan |MCITP - Exchange Server 2010 | Exchange Dictionary(www.exchangedictionary.com)