I needed to retrieve a file from a VHD. With VHDMount I could mount it, get my file, and disconnect.

VHDMount is located in C:\Program Files\Microsoft Virtual Server\Vhdmount

Mount file d:\virtual_drive.vhd as drive letter z:  vhdmount /m "d:\virtual_drive.vhd" z

Unmount all mounted drives, dicarding any changes: vhdmount /u /d All