I am currently able to boot from an external drive or multiboot USB. Taking this concept one step further, I have 3 questions:

1) Is it possible to install and run Windows 10 on a portable external hard drive or USB card with the same functionality of being installed on the internal drive?

2) Is it considered legal to do so or will it affect Windows updates in any way?

3) What are the steps to do that? (please outline steps I can follow so I don't lose a drive in the process). :)

EDIT: My question deals specifically with Windows 10, the legality and method of making it a standalone OS running from an external device and what effect if any it has on Windows Update; questions not dealt with in the other question.

  • The proposed duplicate, especially DavidPostill's answer, covers Win 10, it is legal given that Microsoft provides the mechanism, and presumably, Microsoft has no problem with updating its own OS when installed in a manner provided for by Microsoft. The only piece I can see missing is detailed instructions for doing it, which should be available from Microsoft and would probably be too long to fit the site's format. Can you clarify what is not dealt with, that could be dealt with within the site's scope?
    – fixer1234
    Commented Oct 6, 2015 at 3:56
  • @DavidPostill: Your answer on the proposed duplicate covers Windows to Go, which is described as being for an enterprise environment. Is that meant to imply that WTG is the only solution supported by Microsoft for this (i.e., no solution for a Home Edition user), or does that just describe one possible out-of-the-box solution?
    – fixer1234
    Commented Oct 6, 2015 at 4:05
  • use Rufus to create WinToGo drive from an ISO: rufus.akeo.ie Commented Oct 6, 2015 at 4:16

2 Answers 2


Windows 10 (along with versions of 8 and 8.1) has a feature called Windows to Go. This feature is specific to the Enterprise and Education versions of the OS and allows them to be installed onto a USB drive as a portable Windows Environment.

However, you can do this without needing an Enterprise edition of Windows.

You'll need a few things to start:

  • A 16GB or larger USB drive. Preferably USB 3.0. Microsoft sell certified 32GB drives as well.
  • Installation media. Either a disc or .ISO will do here as you only need the .WIM file from the media.
  • GImageX. This is a graphical frontend to the Windows Assessment and Deployment Kit tool called ImageX. It will let you install the .WIM file onto the USB drive.


  1. Mount your media, either .ISO or disc and navigate to the .WIM file is located, normally at X:\sources\install.wim where X is the drive letter of your mounted media.

  2. Image the .WIM file onto your USB drive by using GImageX. This is fairly straight forward, just make sure you use the correct version (32-bit or 64-bit) of GImageX for your computer. Once GImageX is running, click the Apply tab,load up the source and point it at the drive letter of your USB drive.


This will take a while as this is actually install Windows onto the drive.

  1. Mark the partition as Active using Disk Management.

Mark Partition Active

  1. Next we need to create Boot Entries for the drive. Run a command prompt as an Administrator and navigate to X:\windows\system32 and run bcdboot.exe X:\Windows /s X: /f ALL
    (X is your USB drive).

  2. Done! Restart your computer and boot from your USB Drive.

Source and Images: http://www.howtogeek.com/196817/how-to-create-a-windows-to-go-usb-drive-without-the-enterprise-edition/

  • by the way DISM replaced ImageX awhile ago.
    – Ramhound
    Commented Oct 6, 2015 at 12:20
  • Nice answer! You saved my day. Commented Aug 5, 2016 at 13:50
  • 1
    @Ramhound could you explain how to do this using DISM? the GimageX method didn't work for me
    – crypdick
    Commented Dec 9, 2016 at 19:12
  • @RovingRichard - "it didn't work" doesn't provide me enough information. It also is beyond the scope of this question and wouldn't make a acceptable answer to this question.
    – Ramhound
    Commented Dec 9, 2016 at 20:28
  • 1
    Will this need an additional windows-license-key? If not, what are the limitations of this? Can I use both systems at the same time? When I use the system on my linux machine (or any other), will I have a hard time resolving driver issues manually?
    – verpfeilt
    Commented Jun 22, 2017 at 11:12

Is it possible to install and run Windows 10 on a portable external hard drive?

Yes. That is what "Windows To Go" is for. See my answer to another question Windows OS on external hard drive for much more information.

Windows To Go is a feature in Windows 8 Enterprise, Windows 10 Enterprise, and Windows 10 Education that allows them to boot and run from USB mass storage devices such as USB flash drives and external hard disk drives. It is a fully manageable corporate Windows environment.

It is intended to allow enterprise administrators to provide users with an imaged version of Windows that reflects the corporate desktop. Creation of Windows To Go drives is not officially supported by other Windows editions.

Source Windows To Go

There are various workaround for using Windows To Go with other versions of Windows, see 4 Tools To Create Windows To Go USB Of Windows 10 for example.

Is it considered legal to do so?

Yes. It must be as it is provided by Microsoft.

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