Dual Boot Windows 7 and Windows 8

Tags: Hyper-V, Virtualization, Windows 7, Windows 8

Disclaimer:  To keep the disclaimer short, I’ll just say that this worked for me and it might not work for you.  Attempt the steps in this post at your own risk.  I assume no responsibility for anything that you do in your own system or systems.

It took me less than an hour to get up and running with Windows 8 Developer Preview once I had downloaded it.  As such, I thought it would be nice to write up a quick (re-reading this, quick doesn’t appear to be very accurate) post on what I did to get it up and running.  I’ll start by describing my hardware/software configuration.

My system specs

HP Pavilion dv7 laptop
Intel i7 Processor (x64 a.k.a. 64-bit)
Support for hardware virtualization (this is what makes it possible to boot into a .vhd file)
Operating System:  Windows 7 Home Premium (yep, it’s not Professional)

Now that you know what I’m working with, here’s the step-by-step of what I went through with some lovely screenshots.  Since it is the step-by-step approach, some of the steps might seem very obvious and unnecessary.  My goal is simply to be as thorough as possible, so please keep this in mind (particularly on step #1).

Note:  Throughout these steps, you may be prompted by UAC (User Account Control) for authorization to continue.  Unless otherwise stated, I assume that you click Yes when presented with any such prompts.

    1. Turn on the computer and boot into Windows 7 Home Premium.
    2. Start—>right-click Computer and click Manage
    3. In the left pane, click Disk Management and wait patiently for it to load
    4. In the left pane, right-click Disk Management and click Create VHD
    5. On the “Create and Attach Virtual Hard Disk” dialog, enter the Location, set the Virtual hard disk size, and choose a Virtual hard disk format.  Below is a simple example.
    6. In the bottom, middle pane, you should now see the new disk with some label (mine’s Disk 2) and it will look like the screenshot below.
    7. Right-click the left side of this pane and click Initialize Disk.
    8. On the Initialize Disk dialog, ensure that your disk’s checkbox is checked and that the MBR (Master Boot Record) radio button is selected and then click OK.
    9. Once initialized, it should look like the image below.
    10. Right-click the unallocated space section and then click New Simple Volume…
    11. On the New Simple Volume Wizard dialog, click Next.
    12. The next section of the wizard looks similar to the screenshot below.  Simply click Next here as well.
    13. Assign a drive letter to the volume and click Next.  I chose “W” for “Windows.”
    14. Select the radio button labeled Format this volume with the following settings: and ensure your settings are similar to those in the image below.  Once that’s completed, click Next.
    15. Verify your settings and click Finish.
    16. After a moment of formatting, your new volume should resemble the image below.
    17. At this point, you need to mount the .iso file that you downloaded.  I typically use PowerISO, but you can use any program that you like as long as you can mount the .iso file and explore its contents.
    18. Once you have the .iso file mounted, right-click the mounted drive as you see it in Windows Explorer and click Open.
    19. Open the sources folder and locate the file named install.wim.  You don’t have to do anything with install.wim right now.  Just make a note of the full path to it.  In my example, the full path to install.wim is H:\sources\install.wim.
    20. Next, you’ll need the Windows Automated Installation Kit (WAIK or Windows AIK).  You may download it for Windows 7 here.  There are other versions of WAIK, so be sure you download the appropriate one for your own operating system.
    21. Install WAIK.  You’ll need to mount that .iso file and install it.  This post does not provide instructions for doing that.  However, once it’s installed (assuming you left everything set as the default settings, it should be installed on your machine at C:\Program Files\Windows AIK.  From this point on, I assume that you have WAIK installed.
    22. Start—>All Programs—>Accessories—>right-click Command Prompt and click Run as administrator.  The command prompt will open.
    23. Type the following commands (hit Enter at the end of each command)
      1. cd \
      2. cd "Program Files\Windows AIK\Tools\amd64"  (amd64 is what worked for me and may not be what works for you
      3. imagex /apply H:\sources\install.wim /check 1 W:  (this process can take anywhere from 10-20 minutes…coffee break!
      4. bcdboot W:\Windows
        • This updates your machine’s boot loader so that you can successfully boot into Windows 8.  It also makes Windows 8 the default boot option
        • This one’s brand-new territory for me and I can’t officially advise you to do this.  I’m not an infrastructure guy myself, so the technical details behind this are beyond me.  Again, please attempt this only at your own risk
    24. Reboot your machine.  Upon reboot, you should be presented with a list of available operating systems for you to boot into.  Windows 8 will be labeled as Windows Developer Preview.  Select it from the list and hit Enter.  Once you’ve done that, Windows 8 should walk you through the first time configuration steps and allow you to set your preferences.  Be patient with the first boot as a lot of loading of files takes place and will take some time.  Remember…this is pre-beta.
    25. Now you get to play with Windows 8 and check out some of its new and interesting features!