The following procedures describe how to add a native-boot virtual hard disk (VHD) to the boot menu using the BCDedit tool. If you are adding the VHD to a computer that already has a Windows® 7 installation, you will need to add a boot entry to the menu. If you are adding the VHD to a computer running an older version of Windows, for example Windows Server® 2008, you will need to update the system partition using the BCDboot tool and then edit the boot menu using the BCDedit tool.

To update a BIOS-based computer to include a Windows 7 boot menu

If you are deploying the VHD to a BIOS-based computer without a Windows 7 boot menu, for example, a computer using Windows Server 2008 as the running operating system, you will need to update the boot environment using a Windows Preinstallation Environment (Windows PE) disk before you can configure the system for native-boot VHDs.

  1. Copy the .vhd file to the destination computer. For example, at a command prompt, type:

    copy N:\VHDs\windows7.vhd C:
  2. Use the DiskPart tool in Windows PE to attach the VHD on the destination computer. You can attach a VHD by using the Attach vdisk command. This activates the VHD so that it appears on the host as a disk drive rather than as a .vhd file. At a command prompt, type:

    diskpart
select vdisk file=c:\windows7.vhd
attach vdisk
list volume
select volume <volume_number_of_attached_VHD>
assign letter=v
exit
  3. Use the BCDboot tool, located in the \System32 directory of the VHD image or in Windows PE to copy the boot environment files and Boot Configuration Data (BCD) configuration from the \Windows directory in the VHD to the system partition. On a computer with BIOS firmware, the system partition is the active partition of the first hard disk. For example, to use BCDboot from the VHD image, at a command prompt, type:

    cd v:\windows\system32
bcdboot v:\windows

The BCDboot tool automatically imports information from the existing installation when updating the BCD. The computer is now updated to include a Windows 7 boot environment. You can now follow the steps in the section "To add a native-boot VHD to an existing Windows 7 boot menu" later in this topic.

To update a UEFI-based computer to include a Windows 7 boot menu

If you are deploying the VHD to a UEFI-based computer without a Windows 7 boot menu, for example, a computer using Windows Server 2008 as the running operating system, you will need to update the boot environment using a Windows PE disk before you can configure the system for use with native-boot VHDs.

  1. Copy the .vhd file to the destination computer. For example, at a command prompt, type:

    copy N:\VHDs\windows7.vhd C:
  2. Use the DiskPart tool in Windows PE to attach the VHD on the destination computer. You can attach a VHD by using the Attach vdisk command. This activates the VHD so that it appears on the host as a disk drive rather than as a .vhd file. At a command prompt, type:

    diskpart
select vdisk file=C:\windows7.vhd
attach vdisk
list volume
select volume <volume_number_of_attached_VHD>
assign letter=v
exit
  3. On a UEFI-based computer, the system partition is hidden by default and must be assigned a drive letter before running the BCDboot tool. Use the DiskPart tool to locate the EFI system partition and assign it a drive letter. At a command prompt, type:

    diskpart
select disk 0
list partition
select partition <x>
assign letter=s
exit
    Where <x> is the 100 megabyte (MB) EFI system partition formatted with FAT.

  4. Use the BCDboot tool, located in the \System32 directory of the VHD image or in Windows PE to copy the boot environment files and BCD configuration from the \Windows directory in the VHD to the system partition. For example, to use BCDboot from the VHD image, at a command prompt, type:

    cd v:\windows\system32
bcdboot v:\windows /s s:

The BCDboot tool automatically imports information from the existing installation when updating the BCD. The computer is now updated with a Windows 7 boot environment. You can now follow the steps to add a native-boot VHD to an existing Windows 7 boot menu.

To add a native-boot VHD to an existing Windows 7 boot menu

If you are deploying the VHD to a computer with an existing Windows 7 or Windows Server® 2008 R2 installation, you can use the BCDedit tool to make the new VHD bootable and add it to the boot menu. For more information about using the BCDedit tool, see this Microsoft Web site.

Note:

Before you begin, you can back up your BCD store using the BCDedit tool with the /export option. For example, at a command prompt, type: bcdedit /export c:\bcdbackup
  1. Copy an existing boot entry for a Windows 7 installation. You will then modify the copy for use as the VHD boot entry. At a command prompt, type:

    bcdedit /copy {default} /d "vhd boot (locate)"
    When the BCDedit command completes successfully, it returns a {GUID} as output in the Command Prompt window.

  2. Locate the {GUID} in the command-prompt output for the previous command. Copy the GUID, including the braces, to use in the following steps.

  3. Set the device and osdevice options for the VHD boot entry. At a command prompt, type:

    bcdedit /set {guid} device vhd=[locate]\windows7.vhd
bcdedit /set {guid} osdevice vhd=[locate]\windows7.vhd
  4. Set the boot entry for the VHD as the default boot entry. When the computer restarts, the boot menu will display all of the Windows installations on the computer and boot into the VHD after the operating-system selection countdown completes. At a command prompt, type:

    bcdedit /default {guid}
  5. Some x86-based systems require a boot configuration option for the kernel in order to detect certain hardware information and successfully native-boot from a VHD. At a command prompt, type:

    bcdedit /set {guid} detecthal on

See Also