Booting Your Vista Box From A WIM File Stored Locally

May 13, 2007

Let me first say Happy Mothers Day to all the wonderful Mothers out there hopefully you are having/had a superb Mothers Day!!! Today is Mothers Day in the US if you hadn't guessed.

This is just amazing, this is the third time today that I have found someone already had a solution to a question I was asked just this last week. This is one, managing SMS clients in both workgroup and a domain, and problems with WinPE and RealTek drivers. This is a very cool solution to someone asking me something last week but now I need to figure out if I can boot into WinPE and run VirtualPC.

How to boot a Vista system from a locally stored WIM file

The Windows AIK provides excellent opportunities to create custom Windows PE based images. Those images are provided as WIM files and can be easily converted to ISO files to be burned on CD or DVD. WIM files can also be used to boot from the network using Windows Deployment Services. The Microsoft site also provides procedures to boot a WIM file from USB drive or a clean local hard drive. Unfortunately I was not able to find a complete description how to place a WIM boot image on the local hard disk and provide it as alternative boot option in the Vista boot Menu.
After combining various publications about the subject I managed to extract the procedure to add an option to the boot menu and boot a computer from the WIM file C:\Sources\boot.wim on the local hard drive:

Copy boot\boot.sdi from the Windows Vista installation DVD to C:\boot (By default this folder is hidden in Windows Explorer)

Use the following set of commands to create a ramdiskoptions object in the BCD store. The string "{ramdiskoptions}" is the well-known name for the object's GUID.
bcdedit /create {ramdiskoptions} /d "Ramdisk options"
bcdedit /set {ramdiskoptions} ramdisksdidevice partition=c:
bcdedit /set {ramdiskoptions} ramdisksdipath \boot\boot.sdi

Create a new boot entry.
bcdedit -create /d "Windows PE boot" /application OSLOADER

Step 3 returns the GUID that is associated with the newly created boot entry. It is referred to as NewGUID in the remaining examples. Run the following set of commands to configure the boot entry.
bcdedit /set {NewGUID} device ramdisk=[c:]\sources\boot.wim,{ramdiskoptions}
bcdedit /set {NewGUID} path \windows\system32\boot\winload.exe
bcdedit /set {NewGUID} osdevice ramdisk=[c:]\sources\boot.wim,{ramdiskoptions}
bcdedit /set {NewGUID} systemroot \windows
bcdedit /set {NewGUID} winpe yes
bcdedit /set {NewGUID} detecthal yes
bcdedit /displayorder {NewGUID} /addlast

Now when you boot the system, an extra boot option "Windows PE boot" is presented and can be used to boot from c:\sources\boot.wim