Boot a VHD
With Windows 7 you can boot Windows 7 based VHD file. After having copied the file to your hard drive use the following commands from an administrative console to add the VHD to the boot manager:
bcdedit /copy {originalguid} /d "New Windows 7 Installation"
bcdedit /set {newguid} device vhd=[D:]\Image.vhd
bcdedit /set {newguid} osdevice vhd=[D:]\Image.vhd
bcdedit /set {newguid} detecthal on
And yes, you have to type the brackets around the drive letter.