To mount a VHD file onto your file system, you either ran some very complicated VB (or PowerShell) Script or you used VHDMount.exe that came with Virtual Server. If you’re running Windows 7 (or Windows Server 2008 R2), you can now use Diskpart.
So, from an elevated command prompt, run Diskpart.
Select the VHD in question:
sel vdisk file="c:\users\daven\desktop\xp professional.vhd"
Then attach it to your system:
That’s it. Pretty easy.