Microsoft Exchange Server was designed with backup in mind. Organizations need to back up their messaging data, and they have to be able to restore that information as well. To meet these needs, Microsoft built a full spectrum of data protection options, from traditional

Communications: Data Protection and Disaster Recovery for Exchange Server 2007 -- TechNet Magazine, July 2007

Microsoft released Windows XP Service Pack 3 to publick, the free downloads are avaiable through windows update / technet / msdn. I urge you all to gothrough the sp3 white paper before deploy the sp3, which will help you to understand the changes and updateds on XP. Windows XP SP3 Overview

Microsoft Exchange 2007 Deployment requirements, you must read this requirements before installing the Exchange 2007.

 

Exchange 2007 System Requirements