Introduction

Microsoft’s only server OS, Windows Server, delivers directory services, administration tools, and many other capabilities for building and maintaining a network infrastructure. It is also the OS platform for which all Microsoft server-based applications are built. The most recent version, Windows Server 2008 R2, shipped in Oct. 2009 and made very few changes to the product’s licensing. (See the sidebar “Recent Windows Server Licensing and Packaging Changes“.)

Licensing Windows Server for use within an organization is generally straightforward if hardware virtualization is used sparingly—a Standard or Enterprise edition server license is needed for each physical server machine, and one Windows Server Client Access License (CAL) must be purchased for each user or device within the organization. However, accommodating scenarios involving nonemployees, using the two Windows Server features that are licensed separately (Remote Desktop Services, formerly called Terminal Services, and Rights Management Services), or making heavy use of virtualization are major factors that can complicate Windows Server licensing considerably.