Dual Boot Windows 8 Without Partitioning your HD

Windows 8 consumer preview is scheduled to be released today, that's on February 29, so if you already have Windows 7 installed and you want to try out the new Windows 8, but you aren't ready to format since Windows 8 is still in beta and the chances are that there are some things that are broken.

Then here is the guide on how to get all the goodness of Windows 8 (I'm using Windows 8 Developer preview here) along side Windows 7 without partitioning or formatting your hard disk drive. The only thing that is required in order to dual boot is a hard drive with at least 20 Gigs of free space. All you have to do is create a Virtual Hard Drive using Windows 7 and Install Windows 8 on it using Powershell.

Requirements

• Windows 7.
• 16 GB available hard disk space  (20 GB recommended).

Process

• Creating the VHD.
• Mounting Windows 8 Dvd Image On Virtual DVD Drive.
• Installing Windows 8 On The VHD.

Creating the VHD

To create the VHD, go to a run prompt by pressing Win+R, and type diskmgmt.msc and press enter. Disk Management window will appear.
To create a new VHD, click on the action button in the menu bar, and select Create VHD.

You need to choose a location and size of VHD. Choose Fixed size for better performance.

Once the disk is created, you'll need to initialize the disk by clicking on it and selecting initialize.

Leave the partition style at MBR(Master Boot Record) and click ok.

We now need to create an actual volume on the partition. To do this right click on the black space and select “New Simple Volume”.

A wizard will open, you can just accept all the defaults until you get to this screen. Here change the Volume label to “Windows 8”, then click next and finish.

Now you have a VHD file that is acting like a real Disk drive.

Mounting Windows 8 Dvd Image On Virtual DVD Drive.

The utility that we will use is called Virtual Clone Drive. This utility will let you mount .ISO, .CCD, .DVD, .IMG, .UDF and .BIN files. Download the utility and start the setup process.

Select Yes or OK at the hardware prompt and continue. You might have to restart your computer. Now you should be able to mount any ISO image by just double-clicking on the file. 

Browse to the Windows 8 image and double-click to mount the image.

Installing Windows 8 On The VHD.

Next you need to download this script from MSDN, and then move it to the root of the C: Drive. Right-click on the file and select properties. Click the unblock button in the bottom right hand corner.

Now you need to run PowerShell as an administrator. You can do this by opening Start Menu->All Programs->Accessories->Windows Powershell, right-clicking on the Windows PowerShell, and choosing Run as Administrator.

When PowerShell launches, type Set-ExecutionPolicy RemoteSigned. You will be given a security notice just type “Y” and press enter to accept.

Now type CD C:\ to switch to the root of the drive.

And then type the following command:

.\Install-WindowsImage.ps1 –WIM J:\Sources\Install.wim –Apply –Index 1 –Destination I:\

You should substitute the drive letter that comes after the –WIM for the drive of the mounted DVD image, and substitute the destination drive letter, in our case this is I:\, for the VHD that you created in the first section of this article. Then press enter.

Once it has completed you will be notified.

Now open an elevated command prompt, and type bcdboot.exe I:\Windows (assuming that I:\ is the drive with Windows 8 on it). 

  That’s it now when you boot Windows you will be greeted with the new OS Choosing Screen.