Microsoft announced that Windows 8 will have a new feature for better management of VHD files. Windows 8 will be able to mount VHD file as a hard drive comfortable from Windows Explorer.
Virtual Hard Disk file format
Virtual Hard Disk (VHD) is data container used to store virtual hard drive. Virtual Hard Drive contains all parts of real hard drive, such as disk partitions, file system, files, folders etc.. Virtual Hard Disk format was introduced with Microsoft Virtual PC to store virtualized operating systems. Later Microsoft began to use VHD format in some versions of Windows operating system. Microsoft Windows Vista and Windows 7 use VHD files to store backups. Microsoft Windows Server 2008 uses VHD format with Hyper-V virtualization technology. Windows 7 Enterprise and Ultimate as well as Windows Server 2008 is able to mount and boot from the Virtual Hard Disk file. This feature is named Native VHD Boot.
What will be new in Windows 8?
All options that can be done with VHD file, are available in new Windows 8 Explorer Ribbon menu.
After the VHD file is mounted, Windows 8 shows it as a new hard drive with which it can normally operate.
After the work with virtual hard drive is finished, it can be safety unmounted from Windows 8 with Eject option in Ribbon menu.
Microsoft Windows Vista and Windows 7 are also able to mount Virtual Hard Disk files as a hard drive. This feature is available in the Computer Management application → Disk Management section.