The document discusses how to create a virtual hard drive (VHD) and install an operating system on it to enable dual booting. It describes using Disk Management or Diskpart to create a VHD, installing an OS using Windows AIK, and making the VHD bootable using bcdedit commands. Troubleshooting tips are provided for issues encountered like the OS not booting from the VHD and ensuring the correct device and osdevice settings in the BCD file. Appendices provide details on bcdedit and Diskpart commands.

1. Dual Boot With a
VHD
Virtual Hard Drive
Pip 3/20/14 Troubleshooting an OS

2. Table of Contents
Creating a Virtual Hard Drive .................................................................................................... 3
Installing the Operating System ................................................................................................ 5
Making the Virtual Hard Drive Bootable .................................................................................. 7
Troubleshooting the Process ..................................................................................................... 8
References ........................................................................................................................................12
Appendices
Appendix A - bcdedit commands.................................................................................................13
Appendix B - Diskpart commands .................................................................................................16
Appendix A – Using Diskpart to Create a Virtual Hard Drive ......................................................17

3. Dual Boot with a
VHD
Creating a Virtual Hard Drive
The first step is to create the Virtual Hard Drive
 Right click on Computer and select Manage or otherwise open up Computer
Management
 Select Disk Management
 Click an area of free space in the Partitions Window
 Select the Action menu and then Create VHD
 On the next screen you can specify a location, size and whether the size will be
Dynamically expanding or Fixed. In this case, I’ll put the VHD in the root directory of
the C drive (this makes life easier later in the process since there is no long path to

4. type), give it a size of 20 GB and accept the recommended Fixed Size setting. You
will also be prompted for a name for the VHD and I have called this one Win8
because I’ll be using it to install Windows 8.
 Next we need to initialize the disk. In the partition window you will see that the disk is
there and is shown as not initialized. NB – it can take a while for the VHD to be
created (the message Creating Virtual Disk is displayed at the bottom of the Disk
Management console until the process has been completed – there is a progress
bar displayed as well). Right click it and select Initialize Disk
 Leave MBR selected as the partition style and click OK.
 Next, right click on the partition (which will be shown as unallocated) and select
New Simple Volume.
 Leave the default size setting and click Next.
 Select the required drive letter and click Next.
 Format the partition as an NTFS volume and click Next. For my purposes, I don’t
intend to install an operating system which requires a FAT partition.
 Click Finish

5. Installing the Operating System
To do this, we need a couple of things – we need to have Windows Automated Installation
Kit installed and we need a Windows 8 installation DVD.
We need to copy the installation file from the DVD and put it into the same folder as the
VHD.
The file itself is called install.wim and it is in the sources folder of the installation DVD.
Next, click Start and All Programs and navigate down to the Microsoft Windows AIK folder.
From there click Deployment Tools Command Prompt (right click and run as administrator).
Type the command
o imagex /info c:install.wim
You might recall that with Windows 7 and also Windows 8, the various editions of the
operating system are usually all contained in a single installation DVD and when you run the
installation, the appropriate edition is installed.

6. What we’ve done with the imagex command above is to list these editions. If you scroll up
to the top of the output in the command window you will see Available Image Choices.
Image Index 1 is the Professional edition, 2 is core N. This DVD only has the two editions.
In this case I will be installing the first version, that is, the Professional edition. You should look
through these and ensure you know the index number for the edition you want to install.
The next step is to copy the image files into the VHD which we do with the command
o imagex /apply c: install.wim 1 l:
NB – l (for Lima) is the letter assigned to the Virtual Drive labelled Win8 so you will need to
change this if you have assigned a different letter. The 1 here is the selected edition so this
may also need to be changed.

7. Making the Virtual Hard Drive Bootable
The final step is to make sure that we can boot from the Virtual Hard Drive. This is done from
the same Windows AIK console opened earlier.
The first step in doing this is to use bcdedit and we do this with the command
 bcdedit /copy {current} /d “Windows 8.1 Professional VHD”
This provides us with a unique identifier.
 This has to be copied over to the Virtual Hard Drive with the following command:
o bcdedit /set {4ed990b4-639c-11e3-835c-a164008a71da} device
vhd=[c:]Win8.vhd
 The final step to make the vhd bootable is to ensure the entry in the bcdedit file
which we do with the command
o bcdedit /set {4ed990b4-639c-11e3-835c-a164008a71da} osdevice
vhd=[c:]Win8.vhd
 And one final command to allow the vhd to be moved between devices
o bcdedit /set {4ed990b4-639c-11e3-835c-a164008a71da} detecthal on

8. Troubleshooting the Process
Throughout this process, I did encounter quite a few problems, some of which were easily
fixed and others less so but I thought it might be worth mentioning a few of these whether a
solution was found or not. These might also provide a few pointers for further investigation.
First up, I used two different methods for creating a virtual hard drive. The first was the
method described above and the second was using Diskpart. The Diskpart method is
described in Appendix C.
I found with this method that there was no drive letter assigned to the VHD. I’m not sure if
this was my fault or if the instructions I was following were incorrect, but that was easily fixed
by using Disk Management to assign a letter.
A slightly more serious issue was the operating system. My first attempts were made on a
machine running Windows Server 2008 R2 on which I had tried to install Windows 8 in the
VHD. Everything seemed to work but when I rebooted and select Windows 8 form the
operating system menu, the computer booted into Windows Server 2008 R2.
I decided to ditch Server and install Windows 7 before trying this process again. The second
time, I’ve created two Virtual Drives and installed Windows 8 on one, and Windows Server
2008 R2 on the other. I’m still getting the same thing with Windows 8, but Server worked
perfectly. When I booted into Server, it went through the process of completing the install,
rebooted a couple of times but eventually did boot into Server so this is my first successful
boot of an operating system from a virtual hard drive.
In terms of a cause of the problem, I think there are two possibilities. One is that Windows 8
just can’t be installed in this way. When I tried to find a method for installing Windows 8 onto
a Windows 7 system via a VHD, the solution I found involved creating the VHD and then
installing Windows 8 in the usual way, treating the VHD just like a conventional partition.
Another possibility is that the device wasn’t set correctly. Here is a print out of the BCD file –
this was taken when I had booted into Windows 7 (the current option is the one you have
booted into so viewing this when I have booted into Server doesn’t give me the comparison
I want).
Windows Boot Manager
--------------------
identifier {bootmgr}
device partition=C:

9. description Windows Boot Manager
locale en-US
inherit {globalsettings}
default {default}
resumeobject {635fd2a9-b169-11e3-9899-ff8f8b007df8}
displayorder {default}
{current}
{635fd2af-b169-11e3-9899-ff8f8b007df8}
toolsdisplayorder {memdiag}
timeout 30
Windows Boot Loader
-------------------
identifier {default}
device partition=C:
path Windowssystem32winload.exe
description Windows 7
locale en-US
inherit {bootloadersettings}
recoverysequence {635fd2ab-b169-11e3-9899-ff8f8b007df8}
recoveryenabled Yes
osdevice partition=C:
systemroot Windows
resumeobject {635fd2a9-b169-11e3-9899-ff8f8b007df8}
nx OptIn

10. Windows Boot Loader
-------------------
identifier {current}
device partition=C:
path Windowssystem32winload.exe
description Windows Professional 8.1 N VHD
locale en-US
inherit {bootloadersettings}
recoverysequence {635fd2ab-b169-11e3-9899-ff8f8b007df8}
recoveryenabled Yes
osdevice partition=C:
systemroot Windows
resumeobject {635fd2a9-b169-11e3-9899-ff8f8b007df8}
nx OptIn
Windows Boot Loader
-------------------
identifier {635fd2af-b169-11e3-9899-ff8f8b007df8}
device vhd=[C:]Srv2008.vhd
path Windowssystem32winload.exe
description Windows Server 2008 R2
locale en-US
inherit {bootloadersettings}
recoverysequence {635fd2b0-b169-11e3-9899-ff8f8b007df8}
recoveryenabled Yes
osdevice vhd=[C:]Srv2008.vhd

11. systemroot Windows
resumeobject {635fd2a9-b169-11e3-9899-ff8f8b007df8}
nx OptIn
Actually, you might notice that Windows 8.1 shows as the current OS. This is because when I
booted the system, I did select Windows 8.1.
The first part of the BCD is the loader settings, that is the part of the file that determines
things like the order in which the operating systems appear, which is the default and so on.
The sections labelled Windows Boot Loader represent the operating systems and these are,
in order, Windows 7, Windows 8.1 and Windows Server 2008 R2.
The interesting part is osdevice, which I had set through the appropriate bcdedit command
(similar applied to device). For Server, this is exactly as I had typed it but for Windows 2008,
it simply shows as Partition C: which I would interpret as meaning that the operating system
simply boots from the designated boot partition, hence Windows 7 starts up.
To fix this, it helps that Windows 8.1 is the current operating system on the BCD because it
means I can re-type the commands to set device and osdevice with {current} rather than
the long identifier and it avoids any problems with the wrong entry being updated.
The commands again are
 bcdedit /set {current} device vhd=[C:]Win8.vhd
 bcdedit /set {current} osdevice vhd=[C:]Win8.vhd
 bcdedit /set {current} detecthal on (just for good measure, I still half expect to see
an error message saying ‘I don’t think I can do that, Dave’ but it hasn’t happened
yet!
I’ve typed these in and rerun bcdedit to display the BCD again – just as an aside, I have
rerouted the output to a text file so the command is
 bcdedit >> bcdeditWin8.txt (or any file name you care to provide – bcdedit >>
mytextfile.txt would work just as well and it deposits the text file in the current folder –
since I’m running this from the Windows AIK console that is the PETools folder. The full
path will be displayed on the command line console).
I won’t provide a copy of the full file again but I can see, under the Windows 8.1 entry, that
device is shown as vhd=[C:]Win8.vhd as is osdevice. I’ll now restart the machine and try
to boot up Windows 8 and it boots up correctly.

12. REFERENCES
https://www.youtube.com/watch?v=S6PEb5mH7-c – YouTube video demonstrating the
creation of a VHD using a command line interface
https://www.youtube.com/watch?v=CIsTGARtFEM – YouTube video demonstrating how to
create a VHD via Disk Management
https://www.youtube.com/watch?v=BV9LlC3Wz5A – YouTube video covering the whole
process including creating the VHD and copying the installation files
https://www.youtube.com/watch?v=_XOwQvPFSwA – YouTube UrbanPenguin video
showing how to make a VHD bootable

13. Appendix A
Bcdedit commands
BCDEDIT - Boot Configuration Data Store Editor
The Bcdedit.exe command-line tool modifies the boot configuration data store.
The boot configuration data store contains boot configuration parameters and
controls how the operating system is booted. These parameters were previously
in the Boot.ini file (in BIOS-based operating systems) or in the nonvolatile
RAM entries (in Extensible Firmware Interface-based operating systems). You can
use Bcdedit.exe to add, delete, edit, and append entries in the boot
configuration data store.
For detailed command and option information, type bcdedit.exe /? <command>. For
example, to display detailed information about the /createstore command, type:
bcdedit.exe /? /createstore
For an alphabetical list of topics in this help file, run "bcdedit /? TOPICS".
Commands that operate on a store
================================
/createstore Creates a new and empty boot configuration data store.
/export Exports the contents of the system store to a file. This file
can be used later to restore the state of the system store.
/import Restores the state of the system store using a backup file
created with the /export command.
/sysstore Sets the system store device (only affects EFI systems, does

14. not persist across reboots, and is only used in cases where
the system store device is ambiguous).
Commands that operate on entries in a store
===========================================
/copy Makes copies of entries in the store.
/create Creates new entries in the store.
/delete Deletes entries from the store.
/mirror Creates mirror of entries in the store.
Run bcdedit /? ID for information about identifiers used by these commands.
Commands that operate on entry options
======================================
/deletevalue Deletes entry options from the store.
/set Sets entry option values in the store.
Run bcdedit /? TYPES for a list of datatypes used by these commands.
Run bcdedit /? FORMATS for a list of valid data formats.
Commands that control output
============================
/enum Lists entries in the store.
/v Command-line option that displays entry identifiers in full,
rather than using names for well-known identifiers.
Use /v by itself as a command to display entry identifiers
in full for the ACTIVE type.

15. Running "bcdedit" by itself is equivalent to running "bcdedit /enum ACTIVE".
Commands that control the boot manager
======================================
/bootsequence Sets the one-time boot sequence for the boot manager.
/default Sets the default entry that the boot manager will use.
/displayorder Sets the order in which the boot manager displays the
multiboot menu.
/timeout Sets the boot manager time-out value.
/toolsdisplayorder Sets the order in which the boot manager displays
the tools menu.
Commands that control Emergency Management Services for a boot application
==========================================================================
/bootems Enables or disables Emergency Management Services
for a boot application.
/ems Enables or disables Emergency Management Services for an
operating system entry.
/emssettings Sets the global Emergency Management Services parameters.
Command that control debugging
==============================
/bootdebug Enables or disables boot debugging for a boot application.
/dbgsettings Sets the global debugger parameters.
/debug Enables or disables kernel debugging for an operating system
entry.
/hypervisorsettings Sets the hypervisor parameters.

16. Appendix B
Diskpart commands

17. Appendix C
Using Diskpart to create a Virtual Hard Drive
Another way to create a VHD is to use Diskpart. The method for this is as follows. Ultimately,
it doesn’t matter which method you use because the procedure is going to be exactly the
same once the VHD has been created, formatted and assigned a drive letter.
 The first step is to open a command prompt with elevated user privileges.
 Type Diskpart (enter).
 The command to create a VHD is
o create vdisk file=’path’ maximum ‘size’
o In real terms, the command in this case is create vdisk
file=C:usersadministratordesktopwin8.vhd maximum 20000
 The next step is to select the VHD which you do with the command
o select vdisk file=’path’
o Again, for my VHD this command becomes select vdisk
file=C:usersadministratordesktopwin8.vhd
 And next we want to attach the VHD which we do with the command
o attach vdisk
 We can now create a primary partition with the command
o create partition primary
 The partition is going to be formatted as an NTFS partition and I will give it the label
Win8 and this is done with the following command
o format fs=ntfs quick label=”Win8”
 We can now use the list vol command to view a list of volumes – note this shows the
VHDs created with both the methods but I haven’t assigned a drive letter to the
Win8 VHD.
 This can be fixed by assigning a drive letter through Disk Management.
Note – referring back to Appendix B, you can see that Diskpart does provide a command
to assign a drive letter to a disk drive so you can also use that to fix the missing drive letter or
just remember to type the command when creating the VHD.

18.  The last thing I need to do under the command prompt is to detach the VDH which
is done with the command
o detach vdisk
o Type exit to come out of Diskpart and close the command prompt