I'm trying to use WIM2VHD according to the instructions on Scott Hanselman's blog post to create a Sysprepped VHD image to boot from. I've installed the WAIK, and I have my Windows 7 sources mounted as a virtual drive.

When I try to run WIM2VHD like this:

cscript WIM2VHD.wsf /wim:F:\sources\install.wim /sku:Ultimate /vhd:E:\WindowsSeven.vhd /size:30721

I get the following log:

Log for WIM2VHD 6.1.7600.0 on 11/2/2009 at 10:51:18.16
Copyright (C) Microsoft Corporation. All rights reserved.

MACHINE INFO:
    Build=7600
    Platform=x86fre
    OS=Windows 7 Ultimate
    ServicePack=
    Version=6.1
    BuildLab=win7_rtm
    BuildDate=090713-1255
    Language=en-ZA

INFO: Looking for IMAGEX.EXE...
INFO: Looking for BCDBOOT.EXE...
INFO: Looking for BCDEDIT.EXE...
INFO: Looking for REG.EXE...
INFO: Looking for DISKPART.EXE...
INFO: Session key is E01E1ED7-C197-4814-BDE4-43B73E14FCC4
INFO: Inspecting the WIM...
INFO: Configuring and formatting the VHD...
*******************************************************************************
Error: 0: Cannot derive Volume GUID from mount point.
*******************************************************************************
INFO: Unmounting the VHD due to error...
WARNING: In order to help resolve the issue, temporary files have
not been deleted.  They are in:
C:\Users\Jacob\AppData\Local\Temp\WIM2VHD.WSF\E01E1ED7-C197-4814-BDE4-43B73E14FCC4
*emphasized text*Summary:  Errors: 1, Warnings: 1, Successes: 0
INFO: Done.

Any ideas?