Microsoft Windows Server 2008 Standard R2 with SP1, 64-bit with 5 CALS, OEM

Windows Server 2008 R2
 
Designed to power the next generation of networks, applications, and Web services, Windows Server 2008 R2 and Windows Server 2008 operating systems help you develop, deliver, and manage rich user experiences and applications, provide a highly secure network infrastructure, and increase technological efficiency within your organization.