Install Windows 10/8.1 From External Hard Drive

We have already shown a number of ways to install and test Windows 8.1 and the latest Windows 10 on your PC, including how to install Windows 10 from USB drive, how to clean install Windows 10 from ISO, create UEFI bootable USB of Windows 10, etc.

As many of readers asking to write the best possible to install Windows 8.1 or Windows 10 from an external hard drive, we have come up with this simple guide to show how to install Windows 10 or 8.1 from external hard drive.

We recommend a backup of critical data on the external hard drive as the method requires you format the external drive.

NOTE: In this guide, we have used a PC running Windows 7 to prepare the bootable external hard drive. The procedure is pretty much same on Windows 10 and 8.1.

Make external hard drive bootable to install Windows 10/8.1


Step 1: Connect your external USB hard drive that you want to use as installation media to the PC and backup the data to a safe location as the drive will be erased in the later steps.

Step 2: Open Computer, right-click on the external hard drive icon, and then select Format option to open Format dialog box. Select File System as NTFS, select Quick Format option and click Start button to do a quick format of the drive.

Install Windows 8 From External Hard Drive Step1

Install Windows 8 From External Hard Drive Step2

Click Yes for the confirmation prompt. Once the format is done, you will see “Format Complete” message. Click Ok button.

Install Windows 8 From External Hard Drive Step23

Step 3: We assume that you have a Windows 10/8.1 ISO file. You need to extract the ISO file contents to the root of your external drive. To do this, you need 7-Zip (free), WinZip, or WinRAR software.

Installing Windows 8 From External Hard Drive

Installing Windows 8 From External Hard Drive Step

Install Windows 8 From External Hard Drive Step4

If you have any of the above mentioned zip utility on your PC, right-click on the Windows 10/8.1 ISO file and select Extract files option to extract the ISO file contents to the external hard drive.

NOTE: If you are using 7-Zip software to extract the ISO file, right-click on the ISO > 7-Zip > Extract Files option. Make sure that you are extracting the files to the root the external hard drive.

And if you have Windows 8.1 or 10 DVD, simply copy all files and folders of the DVD to the root of the external hard drive.

Step 4: Now open Command Prompt with admin privileges. To open the Command Prompt with administrator rights you can follow any of these steps:

A. Type CMD in Start menu search box and hit Ctrl + Shift + Enter keys simultaneously.

Install Windows 8 From External Hard Drive Step5


B. Go to Start > All Programs > Accessories. Right-click on Command Prompt entry and select Run as administrator option.

Step 5: In the Command Prompt, type-in the following commands and hit Enter key after typing each command.



bootsect x:

(where “x” is your external hard drive’s drive letter)

Installing Windows 8 From External Hard Drive Step 5

Installing Windows 8 From External Hard Drive Step 6

(this is the message that you get once the process is completed)

Step 6: Exit the Command Prompt, reboot your PC and then follow the on-screen instructions to install your Windows 10 or Windows 8.1 from the external hard drive.




    after struggling so much with the media creation tool, this site solved my problems. Instructions work flawlessly!! Brilliant help!

  2. Arvind says

    Following worked for me:

    1. Just open up a CMD (CTRL+SHIFT+ENTER) — Admin Privileges
    2. You should be in system32 folder by default — run following(here j: is your external drive partition — should be primary and NTFS):
    bootsect /nt60 j: /force
    3. Use 7-Zip to unzip ISO into J: (root)
    4. In CMD, open following:
    list disk —> Find out disk no. for your external harddisk (mine was Disk 1)
    select disk 1
    list partition —> Find out partition number for your partition J: (mine was Partition 3)
    select Partition 3
    5. Exit the CMD and Reboot from External Drive using BIOS Boot options (HP — F9, Dell etc – F12)

    Hope This Helps Folks!

  3. chill says

    Thanks a million Pal…Worked flawlessly with Windows 10 Installer Creation onto my

  4. aayush says

    wow amazing everything worked smoothly i loved the simplicity of the site its detailed steps and i just loved it everything done for free otherwise i would have to spend a minimum 6500rs or 100$

  5. Brian Ng says

    I experienced the BOOTMGR and NDLTR errors, and to solve these issues:

    1. Use free easeUS partition master tool to set target partition (X:) as Active and Convert to Primary. After apply, you may have to restart to process the queue.

    2. Enter CMD with Administrator privilege and enter these commands:
    C:\> X:
    X:\> cd/boot
    X:\boot\> bootsect /nt60 X:

    3. Before booting, enter bios setup to set first boot device to your external HDD.

    4. Now you’re able to boot from your external HDD to setup windows.

  6. Cenk from france says

    Omg omg omg
    Thank you so much admin
    Since 3 days i cant repear my computer
    And know thanks to you I solve this problem

  7. Jordi says

    I find it funny that the intro says you dont have to format your EHDD and then at step 2 boom, format it!

    “The advantages of using this method is that we are not formatting the drive to make it bootable. So, if you have any data on your external hard drive, you need not worry! But we recommend a backup of critical data on the external hard drive just to be on the safer side.”

    “Step 2: Open Computer, right-click on the external hard drive icon, and then select Format option to open Format dialog box. Select File System as NTFS, select Quick Format option and click Start button to do a quick format of the drive.”

  8. Ayyash says

    I cant even get to make it load from External driver after doing all suggestions, it wont see external on start up, is something set in Bios that prevents it from firing? I went into advanced setup and made Boot from External Device enabled, and put it higher in the order, yet nothing…. the files on the root include an autorun.inf and setup.exe, am I missing soemething?

  9. blag says

    So, im trying to follow this but what is happening is the installer is installing the boot info on the drive i am installing windows from, thus the system will not boot unless i boot from my external. How do i fox this+?

  10. cam says

    Thanks for wasting my time. It failed. It says “Disk read error”, and i followed the guide and NOTHING is wrong with my device.

  11. admin says

    You can do a full format to remove all bootable files and restore its original condition.

  12. Dreamade says


    i tried to install windows 8 64-bit with this guide. But my current OS is win 7 32-bit so i get an error in command line. any suggestion?

  13. Peppe says

    I needed to boot from a External Hdd, because I had no CD/DVD-drive and no flash usb. This worked for me:
    Use MiniTool Partition Wizard, a free tool!
    – create a boot disk in partition wizard
    – boot your computer with boot disk in
    – copy the win8-iso-partition (do the step 5 thing as well, but as described in comments) from external hdd to the computer hard drive.
    – set partition as primary and active
    – reboot, and boot from local drive

  14. Noel says

    I got this thing working, the instructions are wrong tho.

    First mark the partition you want to use as “Active” you can do this in your Local Storage Management or trough DiskPart.

    After that use the following commands in CMD

    X: (Where X is your drive letter)
    bootsect /nt60 X:

    You should now be able to install windows 8 from your external HDD

  15. andy says

    fuk now my external harddrive is dead, asking me to reformat now i have important informations in it is there a ways to remove those commands in harddrive and get my informations back ?

    bootsect x:

    those commands in harddrive and get my informations back ?

  16. Olmo says

    You should run the bootsect.exe from another drive than the one you want to make bootable.

    bootsect needs to lock the drive to run properly. so if you run it from the same drive as you want to make bootable it fails.

  17. Nils says

    In order to boot from my USB-device, I had to check my External HDD as Active in Disk-management

  18. loPan says

    I realize that most of these posts are old but this is for the benefit of anyone who might read this from a search.

    1st and foremost – you don’t need to reformat your whole external drive, this is wasteful and unnecessary. If the drive is in one partition simply take all your folders and put them into a new folder (that is not named anything that is on the .iso file, call it mystuff or whatever) to get them out of the way and make things easier to organize. Then simply mount the .iso and extract the contents to the external drive.

    From there go to step 5: and use the command bootsect x: /nt60 where x is the external drive.

    From there reboot and be sure to press the appropriate fkey to boot from your external drive. On my computer it’s F9 but it varies according to BIOS. Usually you will see an option for “boot menu” when the computer is starting up.

    Alternately you can go into bios setup and reorder your boot order to make the computer boot from usb device before the hard drive.

  19. Aldo says

    I already follow all the steps but when i reboot my pc.. it goes directly to windows 7 start, what can i do?

  20. amit says

    I have partitions on my external USB hard disk. Can i boot from it without formatting whole drive??
    pls help………!!!!!!!!!

  21. robert says

    I got to the install screen and after I click install now it tells me it can’t find any drivers. Can’t go anywhere from there.

  22. GoodSmith says

    The author claims in his article that no formatting is needed, yet later in the instructions he mentions formatting the external hard disk!!

    Also the bootsect command thing which Smedrick cleared out. You might even need to run it in forced mode
    bootsect /nt60 x: /force

    However, none of this is working with me yet. My netbook still can’t boot from my 1TB external hard disk after following all these instructions, and I don’t want to format it because I have 100s of GBs of data on it that have no other place to backup.

    I will keep you posted if I find a solution.

  23. Smedrick says

    @ admin

    You’re wrong, User is (partially) correct. Step 5 does nothing the way you wrote it. Just look at your screenshot…all it did was show you the usage instructions. It should be “bootsect /nt60 x:”

  24. Mark says

    I followed the instructions but when i reboot i get no option to install windows 8… it just goes straight into windows 7

  25. User says

    Thank you for your efforts.
    I was wondering about step 5, I guess the command should be: “bootsect X: /nt60” !!?

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