In Windows® 7 and Windows® 8, a virtual hard disk can be used as the running operating system on designated hardware without any other parent operating system, virtual machine, or hypervisor
I also discovered that if you install Windows 7 Ultimate onto a VHD, you can boot just fine. However, if you install Windows 7 Home Premium or Windows 7 Professional onto a VHD, the install will work fine, but when you attempt to boot either version from a VHD you will receive the error message License Error - Booting from a VHD file is not supported on this system.
So it appears that the Native VHD Boot feature is available in all versions of Windows 7, but that only Windows 7 Enterprise and Windows 7 Ultimate can boot from VHD.
rem -- Create_VHD.txt -- create vdisk file="C:\Test.vhd" Maximum=15360 Type=Expandable attach vdisk automount disable create partition primary online volume format quick fs=ntfs label="Test Label" automount enable assign letter=M exit
rem -- Create_VHD.cmd -- cd /d "%~dp0" DISKPART /s Create_VHD.txt Exit