The hardware requirements for Hyper-V are not much different from the base requirements for Windows Server 2008. Windows Server 2008 is available in both 32-bit and 64-bit configurations, while Windows Server 2008 R2 is 64-bit only. Hyper-V, however, is only available on the 64-bit editions of Windows Server. The CPU must have the necessary virtualization extensions available and turned on in the BIOS. Both the major processor manufacturers (Intel and AMD) have CPUs with these extensions available.
In addition, the CPU must support hardware-enforced Data Execution Prevention, or DEP. For Intel processors, this requires enabling the XD bit; for AMD processors it is the NX bit. These functions are found in your computer’s BIOS settings.
Memory is another consideration. In addition to the underlying (or “host”) Operating System, the virtualized (or “guest”) operating system also requires its share of RAM; the more guests you plan to run simultaneously, the more memory you need. A good minimum to aim for is 4 GB of RAM, as this leaves sufficient memory for the guest and one or two hosts. HP has a sizing tool available at http://g3w1656g-vip.houston. hp.com/SB/Installs/HyperV_SizingTool.zip. Again, this is a minimum number. We seem Microsoft recommendations as high as 8 GB.
For hard drive space, you similarly want to consider the needs of the host and each guest operating system. In the case of the guests, you need enough disk space to accommodate all of the installed guests, applications, and data simultaneously, regardless of how many you intend to run at the same time.
For best results, Hyper-V requires a minimum of two physical network adapters: one for hypervisor management and one for VM to network connectivity. If you plan to cluster your devices, install a third adapter.
Source of Information : Elsevier-Microsoft Virtualization Master Microsoft Server Desktop Application and Presentation