Boot From VHD – Replacing Vista or Windows 2008 Bootloader with Windows 7 Bootloader

Windows 7 introduce a cool feature enabling us to boot OS on bare metal from a VHD file. This is done by using the new bootloader which comes with Windows 7.

So many people out there (specially techie) who might have vista or windows 2008 as their OS might want to try out Windows 7 or already might have it as a VHD. This could be achieved without having to go through re-partitioning, re-formatting and without loosing old OS. The only thing we need to do is to load Windows 7 bootlaoder replacing the existing Vista or Windows 2008 bootloader. This will not work with Windows 2003 or XP as they use ntldr as boot manager to load OS. With Vista/Win 2008 Microsoft changed the boot manager with bootmgr which is in you system partition. bootmgr does reads its configuration from bcd file. The bcd file can be edited with command line tool bcdedit.exe

You will need following things as we go ahead

– Windows 7 Media for platform you are using i.e. x86/x64 (any version will work)

– A VHD file having Windows 7 already installed. (How to make one?)

Let start the ball rolling

COPYING BOOTLOADER

1. Insert the bootable Windows 7 media into CD-ROM and boot from it

2. Select your language country and then click “Next” on welcome screen

3. On Installation screen click on “Repair your Computer”

4. On “System Recovery Options” select “Restore your computer using a system that you created earlier.” and click on “Next”

5. On “Re-image Your Computer” click “Cancel” and then again click on “Cancel”

6. On “System Recovery Options” click on “Command Prompt”

7. Once you get to command prompt we need to know drive letter assigned to you CD-ROM, so type “diskpart” and hit enter

8. Then at DISKPART prompt type “list volume”

9. Note drive letter assigned to your CD-ROM (as highlighted in picture as “E”)

10. Find which is you system drive where you can find file “bootmgr”. You can change the command prompt to each drive letter and run command “dir /ah”. In my case as screen shot below the file “bootmgr” is located in “C” drive.

– Now you need to run the following command “attrib –s –h –r c:\bootmgr”

– Execute the following command “xcopy /y /h c:\bootmgr c:\bootmgr.bak”

11. On command prompt change the drive to cd-rom in my case it is “E” so type “e:” and enter, make sure the you are root folder of CD if not then run “cd\”

– Execute the following command “xcopy /y /h e:\bootmgr c:\bootmgr”

12. Now on command prompt change your drive letter to installation drive which should be “X” so type “X:” and hot enter.

– Change the directory to “cd\windows\system32”

– We need to replace file “bcdedit.exe” for vista with version from Windows 7.

– Find you vista sytem32 directory which in my case is “D:\Windows\Ssytem32”

– backup your original file, execute the following command “xcopy /y /b d:\windows\system32\bcdedit.exe d:\windows\system32\bcdedit.bak” and press “f” at prompt to say xcopy that this is a file

– execute the following command to copy windows 7 version of the file “xcopy /y /b bcdedit.exe d:\windows\system32\bcdedit.exe”

 

CREATING BOOTLOADER BCD ENTRY TO BOOT FROM VHD

1. Run command “bcdedit /v”

2. Copy the identifier (GUID) for your current OS into clipboard, in my case it was “{68739be9-9d9a-11de-b17d-f00e6f1861b1}” marked in yellow

3. Execute command “bcdedit /copy {68739be9-9d9a-11de-b17d-f00e6f1861b1} /d “Windows 7””

4. Copy the new GUID to clipboard assigned to the copied entry in my case(marked blue) it was “{68739bec-9d9a-11de-b17d-f00e6f1861b1}”, the only difference was 8th character so do not miss this

5. Execute command “bcdedit /set {68739bec-9d9a-11de-b17d-f00e6f1861b1} device vhd=[d:]\MyVHD\Windows7.vhd”

NOTE: I assume that you already had a vhd file copied to your D: in my case this was the only data partition i had on my system where i had kept this vhd. Make sure that the drive letter is in square bracket.

6. Execute command “bcdedit /set {68739bec-9d9a-11de-b17d-f00e6f1861b1} osdevice vhd=[d:]\MyVHD\Windows7.vhd”

7. Execute command “bcdedit /set {68739bec-9d9a-11de-b17d-f00e6f1861b1} detecthal on”

8. Type “exit” on command prompt

9. On “System Recovery Options” click on “Restart”

 

So did this post answer your question?

– Loading Windows 7 Bootloader without loading Windows 7

– How to add a Windows 7 VHD to Vista’s boot manager menu

– Replacing Windows Server 2008 bootloader with Windows 7 bootloader to enable booting from vhd files

– windows 7 creating boot loader partition

– Native Boot to Windows 7 in VHD from Windows Vista