I wish to install Windows 8 on a laptop's external USB HDD. Is this the best and safest way to do it? http://www.youtube.com/watch?v=vo27iz1Q3x8

  • Have you tried it? Unless you select the wrong partition it wouldn't effect the MBR of the system partition.
    – Ramhound
    Apr 30 '13 at 14:55
  • @Ramhound How do I make sure I select the correct partition?
    – AturSams
    Apr 30 '13 at 15:22
  • By making sure you select the parition that is your external hdd.
    – Ramhound
    Apr 30 '13 at 15:35
  • I couldn't get it to work. It never allowed me to go into command prompt. I will give PWBoot a chance now.
    – AturSams
    Apr 30 '13 at 16:29

It's possible: here's how to install a portable version of Windows 8 on a USB hard drive that you can take anywhere.

The Enterprise version of Windows 8 has a feature called Windows To Go that lets you install a portable version of Windows on a "certified" flash drive. Unfortunately, most of us don't have the Enterprise edition of Windows 8, nor a certified flash drive. However, there is a tool called WinToUSB that can essentially do the same thing, no matter what version of Windows you have. Here's how it works.

This allows you to install and run Windows operating system on a USB hard drive or USB flash drive, using an ISO image or CD/DVD drive as the source of installation. WinToUSB also support creating bootable WinPE USB drive, it can help you to transfer the contents of WinPE to the USB drive and make the drive bootable.

Reference: http://www.techproceed.com/2013/11/install-and-run-windows-on-usb-external.html


I tried different guides on the web and most of them were incomplete or rather poor imho. The best guide that walked me through a surprisingly simple process of installing Win 8 onto an external HDD is in the following link:


Credits to TonyTones. I wish to make a tiny comment. In order to create the boot and prepare your external windows Installation's MBR, you may need to run the bcdboot by boothing from your Windows DVD and hitting shift + F10 and the checking what are the correct drives for your installation. I also disabled my internal HDD completely for extreme safety. So for me it was something like:

cd Windows\System32
bcdboot D:\Windows /f ALL /s C:

I am pasting all instructions here for safe keeping in case anyone needs to do this: 1. Launch the Deployment Tools Command Prompt with administrative rights from the Start Menu. It can be found under All Programs and then Microsoft Windows AIK.

  1. Make sure that your USB Drive is plugged in and then type in diskpart and hit Enter.

  2. List the available disks by running "list disk" and you should see your usb device.

  3. Select your USB drive by typing "select disk #" and hit Enter. For example, “select disk 3”.

  4. Clean the partitions on the disk by typing "clean" and hit Enter.

  5. Now create the boot partition by running the following command:

    create partition primary size=350

  6. Now create the OS partition by running the following command to create a partition taking up all remaining space:

    create partition primary

  7. The boot partition needs to be formatted, configured and assigned a drive letter, run the following commands:

    select partition 1 format fs=fat32 quick active assign letter=b

    (if the b drive letter is already in use on your PC, substitute a different letter and replace b with your letter throughout the rest of this guide)

  8. The same must be done for the OS partition, run the following different commands:

    select partition 2 format fs=ntfs quick assign letter=o

    (if the o drive letter is already in use on your PC, substitute a different letter and replace o with your letter throughout the rest of this guide)

  9. Exit Diskpart by typing Exit.

  10. Install Windows using Wim Installer and imagex on the correct drive



  11. The boot manager needs to be installed on the boot partition with the help of the bcdboot utility. Run the following command:

    o:\windows\system32\bcdboot o:\windows /f ALL /s b: You may need to boot from the Windows CD and hit Shift + f11

  12. Reboot your computer and test your new Windows 8 To Go device built on Windows 7. Make sure the PC is configured to boot to USB before your local hard drive.


I installed windows onto my external HD with the help of WinToUSB. It was very easy for me. It had no effect on my MBR. Hope my way make you feel it easier. The installation steps are as follows.

  1. Download WinToUSB Installer
  2. Run the installer as administrator to install WinToUSB
  3. Open the installed WinToUSB application
  4. Choose a desired windows iso file. Click Next

choosing iso image - window

  1. Choose a desired installation medium (external HD). Click Next

choosing hard disk - window

  1. Installation will follow. You may use your portable windows after installation.

installation - window

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