Unable to add VHD through Virtual Disk Manager or VBoxManage

[bronsoja]

I am trying to add the VHDs for that microsoft provides here ​http://www.microsoft.com/downloads/details.aspx?FamilyID=21EABB90-958F-4B64-B5F1-73D0A413C8EF&displaylang=en to test ie6 and ie8 web application compatibility. They work fine in VPC.

I'm running 64bit VBox on 64bit Vista, I have a Win Server 2K8 image that works. I do have hardware virtualization enabled.

Here is the output when i try to add the disk image through VBoxManage:

C:\Program Files\Sun\xVM VirtualBox>VBoxManage.exe registerimage disk "d:\misc\v
pc\xpsp3-ie6\XP SP3 with IE6.vhd" -type normal
VirtualBox Command Line Management Interface Version 2.1.0
(C) 2005-2008 Sun Microsystems, Inc.
All rights reserved.

[!] FAILED calling virtualBox->OpenHardDisk2(filepath, hardDisk.asOutParam()) at line 897!
[!] Primary RC  = E_FAIL (0x80004005) - Unspecified error
[!] Full error info present: true , basic error info present: true
[!] Result Code = E_FAIL (0x80004005) - Unspecified error
[!] Text        = Could not open the hard disk 'd:\misc\vpc\xpsp3-ie6\XP SP3 with IE6.vhd'.
VDI: invalid pre-header in 'd:\misc\vpc\xpsp3-ie6\XP SP3 with IE6.vhd' (VERR_VD_VDI_INVALID_SIGNATURE).
VD: error opening image file 'd:\misc\vpc\xpsp3-ie6\XP SP3 with IE6.vhd' (VERR_VD_VDI_INVALID_SIGNATURE)
[!] Component   = HardDisk2, Interface: IHardDisk2, {ed6e2525-c2fd-42a4-917a-7a9045ac9e15}
[!] Callee      = IVirtualBox, {339abca2-f47a-4302-87f5-7bc324e6bbde}

[bronsoja]

Copy of error message that isn't mangled.