At this years CES, Microsoft not only unveiled Windows 7 Beta to the public but also released the beta version of their next Server Operating System – Windows Server 2008 R2 (internally known as Windows 7 Server).
Windows Server 2008 R2 will be the next version of the Windows Server operating system from Microsoft, building on the features and capabilities set of the current Windows Server 2008 release version.

Microsoft has released Windows Server 2008 evaluation VHD (Virtual Hard Drive) images for Hyper-V which as of now is available for download from Microsoft Download Center. VHD format is the common virtualization file format used by virtualization software’s from Microsoft like Virtual PC, Virtual Server 2005 and Hyper-V