System Requirements for Windows Server 2008 R2 (source: MS-Elearning)

Windows Server 2008 R2 has system requirements similar to Windows Server 2008, but Windows Server 2008 R2 runs only on 64-bit processors. Although Windows Server 2008 R2 can be installed on a computer with 512 megabytes (MB) of RAM, the computer can use up to 8 gigabytes (GB) for Windows Server 2008 R2 Foundation, 32 GB for Windows Web Server 2008 R2 or Windows Server 2008 R2 Standard, and up to 2 terabytes for Windows Server 2008 R2 Enterprise or Windows Server 2008 R2 Datacenter. System requirements vary between Full Installation and Server Core installation. You can perform an upgrade to Windows Server 2008 R2 from Windows Server 2003 SP2 or a newer server operating system, or you can perform a clean installation of Windows Server 2008 R2. A clean installation is the only option if the previous server is running on a 32-bit processor.




A Windows Server 2008 R2 upgrade is possible from previous 64-bit server operating systems such as Windows Server 2003 R2, Windows Server 2008 SP2, and Windows Server 2008. It does not support upgrades from older operating systems and cross-architecture—32-bit to 64-bit; cross-language—German to English; and cross-edition—Windows Server 2008 Enterprise to Windows Server 2008 R2 Standard. It also does not support upgrade from Itanium-based systems.



Windows Server 2008 R2 expands CPU support to run up to 256 logical processors in a single server. Hyper-V in Windows Server 2008 R2 can access up to 64 logical CPUs on host computers. This can help in increasing virtual machine consolidation ratios per physical host. In addition, Hyper-V supports the latest CPU technologies and advanced storage technologies, including storage area network (SAN) management and solid state devices. Windows Server 2008 R2 can boot from SAN or VHD.



Component Requirement

Processor

Minimum: 1.4 GHz (x64 processor) or faster (Limited 1 processor for Foundation)



Memory

Minimum: 512 MB of RAM

Maximum: 8 GB (Foundation), 32 GB (Standard, Web Server), or 2 TB (Enterprise, Datacenter, and Itanium-based systems)



Disk Space

Minimum: 32 GB or more



Display and other Peripherals

DVD Drive

Super-VGA (800 × 600) or higher-resolution monitor

Keyboard and Microsoft mouse or compatible pointing device

Internet access (fees may apply)