Windows Server R2 Enterprise Edition is the premier platform for business-critical applications. Windows Server 2003 R2 Enterprise Edition builds on the standard features found in the Windows Server 2003 R2 family by adding features designed to increase the reliability scalability, security, and manageability of enterprise applications. This paper provides an introduction to the major technical features in Windows Server 2003 R2 Enterprise Edition and discusses the application of those features to mission-critical applications, such as e-mail, databases, and business applications.