We are currently running Exchange Server 2007 SP1 with Hub, Client and Mailbox roles on a Windows Server 2003 Std. Ed. server that has 4GB of RAM. I just read the article "Planning Memory Configurations". Cut to the chase, I've already ordered 16GB of memory to put into the server. The question is, if the OS only recognizes up to 4 GB, is Exchange going to be able to recognize the rest?Do I need to upgrade the OS to 2008? What do I need to do to make full use of the 16GB?

Hi Melissa, Which edition of Windows do you use? 32 or 64 bit? Windows 2003 Standard Edition 64bit supports 16GB Windows 2003 Standard Edition 64bit SP1/SP2 supports 32GB Reference: Memory Limits for Windows Releases http://msdn.microsoft.com/en-us/library/aa366778.aspx However Exchange 2007 (sp1) 32bit edition is not supported in production environment too. Reference: Exchange Server 2007: Platforms, Editions, and Versions http://technet.microsoft.com/en-us/library/bb232170(EXCHG.80).aspx

Thank you, the link you provided was very helpful and you answered my question. I was unable to find this document or one like it on my own.