Exchange 2010 Prerequisites

http://technet.microsoft.com/en-us/library/bb691354.aspx

This topic provides the steps for installing the necessary Windows Server 2008 Service Pack 2 (SP2) or later or Windows Server 2008 R2 operating system prerequisites for all Microsoft Exchange Server 2010 server roles. It also includes the steps for installing the Windows 7 and Windows Vista operating system prerequisites for the Exchange management tools.