Windows 7 - Boot from a VHD using Windows 7

   Information

Windows 7 includes support for creating, mounting and booting from VHD images but not many seem to know how to use this functionality to boot VHDs at boot time... I will detail the steps required to have another OS bootable using Windows 7...

While all Windows 7 editions can create and attach a VHD, only the Windows 7 Ultimate and Enterprise editions support booting from a VHD.

   Warning

This only works with Vista and Windows 7 VHD images!

If you do not have a good knowledge of how to reset your VirtualOS configuration like HAL type and driver configuration then your VHD will fail to boot, It must be cleaned of VirtualOS configuration correctly before windows 7 can boot your VHD!!

Step 1: Begin by following this Tutorial to create a VHD: Virtual Hard Disk - Create and Attach VHD


Step 2: Open a elevated command prompt.


Step 3: Copy and Paste this command below and press Enter.

bcdedit /copy {current} /d "VHD_Boot"

If the command succeeds, BCDEdit displays a message similar to the following:

The entry was successfully copied to {CLSID_Number}

Take note of the CLSID number as you will need this during the next step

Step 4: Then type this command below and press Enter.

bcdedit /set {CLSID_Number} osdevice vhd=[C:]\disk1.vhd

Step 5: Thats it, You can now boot VHDs using Windows 7
To confirm the settings simply type bcdedit

If your VHD is configured correctly You can reboot and select the extra boot-option to boot from your VHD

   Warning

VirtualPC VHDs can not be used for booting with Windows 7 because VirtualPC uses a Pentium 3 HAL and this prevents them from being used as boot media, You can however use this Tutorial: Virtual Hard Disk - Create and Attach VHD and create then mount a VHD for use with VMWare Workstation....

You simply set VMWare workstation to use a Physical Disk, you can then Install a separate OS onto this mounted VHD for use with Windows 7.

   Tip

You Must reset your VHD VirtualOS configuration like HAL type and driver configuration or your VHD will fail to boot!!! It must be cleaned of VirtualOS configuration correctly before windows 7 can boot your VHD!!

   Note

There are still many bugs associated with VHD booting with Windows 7 at this time, I suspect Microsoft will be releasing a new Version of VirtualPC that's able to manage this entire process of creating, installing and booting separate VHDs at boot-time easily and without so many problems