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Make a Bootable External Hard Drive and Install Windows 7/8

Step 1: Format the Drive
Just place the flash drive in the USB port of your computer. Open command prompt (cmd). You can do that by pressing WINKEY+R, right click on the listed file and click on “Run as administrator“.
Enter the following commands in the same order as I did here:

list disk
select disk z (where z is the number corresponding for your USB disk. You have to replace it with the corresponding letter from your own system).
create partition primary
format fs=fat32 quick

Diskpart Bootable USB

Please be careful using the select command (so you don’t select and format your hard disk instead)

Diskpart External Hard Disk

If everything goes well, this is how your cmd screen will look like

Step 2: Mount The Windows 8 ISO Image Into A Virtual Drive

If you don’t have a physical optical drive you should mount the image into a virtual drive. You can install and use PowerISO

Step 3: Make The External Hard Disk Bootable

I’m assuming that F is your drive letter with Windows 8 ISO image and G: is the location of your external hard disk (or flash drive) . Open the command prompt screen (as administrator) and type the commands:

cd boot
bootsect.exe /nt60 g:

External Hard Disk Bootable

Also, don’t forget to triple check the target location so you don’t accidentally delete the boot sector of your hard disk

Step 4: Copy The Installer Files

After the above step, don’t close the command prompt (at least not yet). At this moment your new external hard disk or flash drive is bootable but you need to execute one more command in order to transfer the files to your new drive. You have to type the following command line:

xcopy f:\*.* g: /e /f /h

Again replace the drive letters with the ones that apply to you. Alternatively you can copy all the files in the virtual drive to the flash drive or external hard drive by using Windows Explorer, but using XCOPY ensures that system and hidden files are also copied.

Step 5: Boot Off The External Hard Drive or USB Flash Drive

To use and boot from your newly created drive on your netbook or computer, first you have to set your computer you must set it to boot through the USB flash drive. In order to do this shut down your computer, go in the CMOS setup by pressing the “DEL” or “F2″ key when the computer power on, without unplug the newly created external hard drive or USB Flash Drive from the machine. Set the device as the primary boot option, save the changes BIOS and restart. On newer computers you can boot from the device without entering into BIOS by pressing either “ESC”, “F9″ or “F11″ (different key on different manufacturers).

External Hard Drive bootable

Now you can install Windows as usual. Please be aware that if you’ve changed the boot sequence in the BIOS, remember to change it back as it was after copying the files (usually after first automatic reboot).



  1. hello. whenever i did the bootsect.exe /nt60 g: command i get the following error: ”This tool can only be run on systems booted using a PC/AT BIOS. This system
    was booted using EFI or some other firmware type.” is there a command for such cases as these for EFI?

    • I HAVE THE SAME PROBLEM AT FIRST try to close your cmd and try to open it with a right click select RUN AS ADMINISTRATOR .

    • Nope it works in my case

      • I am running the CMD as an administrator. The error is still present. Any work arounds?

  2. Thank you very much for this tutorial. It helped a lot!

  3. wow seems to complicated i do this years ago for win 7
    if u have hdd that already in ntfs,primary, and active (if not, do it with partition tool like minitools)
    just copy all win7 file in ISO to that HDD
    rename the bootmgr (not the .efi file) to ntldr and u done
    doesn’t need any fancy cmd command.

    • It works. But I boot it up in safe. Many many thanks!!!

  4. bonjour,
    je suis embêtée:

    j’ai le message “The target volume does not support symbolic links” après avoir fait “xcopy f:\*.* j: /e /f /h” où j est mon usb drive et f le disque virtuel où se trouve l’iso de windows 7; ça a marché pendant 12 lignes puis ce message s’affiche et je suis le bec dans l’eau
    svp éclairez moi si vous pouvez
    merci d’avance

  5. Sorry, I will repeat in English: when I do the command: “xcopy f:\*.* j: /e /f /h” where f is my virtual cd drive where the iso of windows is situated and j is my usb drive which I want to make bootable, it get 12 lines which are working alright then it says: “The target volume does not support symbolic links”… I am stuck, please help me if you know what is to be done
    thank you in advance

  6. Hi,
    I have a question, if i do that is the window going to use the license that has I my BIOS to install?
    Or do i have to buy another key for it?

  7. How can I do this with wary Linux iso ?
    “path not found” gets displayed when I type in cd boot.

  8. Had a ton of trouble getting a bootable iso for windows 10 to work so figured I had nothing to lose by trying this…. the header on this helper should read for Windows 10 as well. It worked like a charm and I managed the clean install on a new drive – thank you.

  9. hello
    in the bootset.exe/nt60 g:
    i get this msg : this version of H:\boot\bootsect.exe is not compatible with the version of windows…….

    • from where you try this command from your pc or from your iso?

    • You are mixing 32bit 64bit

  10. I have a system on which Win 10 is installed in UEFI. In an external harddisk, I want to install Win 7 without affecting Win 10 in any way whatsoever so that when I connect external harddisk, I should be able to boot win 7 and when it is not connected, win 10 should be bootable. Any ideas?

    • it cant be done as to load windows system always chooses the primary bootable device ,and external hard drive cannot be primary bootable drive

  11. the xcopy command stated does not copy every thing better to just copy and paste everything

  12. I can’t seem to boot off of the flash drive.
    When I alter the boot sequence, Windows Boot Manager tells me it failed to read ‘\Boot\BCD’. How do I fix this?

  13. I tried what you said and it’s works no more cmd etc. thanks

  14. Virtual Disk Service error:
    the volume size is too big.

    how do I fix this?

    thank you for your time!

  15. Well that was clear as mud.. I mean, coming from someone inexperienced, you cold have explained the following:

    Step 2: Mount The Windows 8 ISO Image Into A Virtual Drive

    And in step 3 it says “I’m assuming that F is your drive letter with Windows 8 ISO image and G: is the location of your external hard disk (or flash drive).”
    Shouldn’t they be the same, the drive letter and the hard disk letter?

    I just stopped after that and went looking elsewhere.

  16. This tutorial is actually very easy to understand and use, I’m literally only commenting to point out that those of you who can’t understand, shouldn’t be playing with cmd to begin with… mounting a virtual drive is a concept thats been around since windows xp… Of course back then we used magic/power ISO. Riley, your second question, literally exists because of the fact you had question #1… No, the drive your COPYING TO is not going to be the same drive your COPYING FROM…. Anyway, thanks for this tutorial. it also helped me learn a few cmd commands!

  17. Hi,

    I have 1 TB External HD, I would like to create partition 500GB each and make 2nd part as bootable HD. Is it possible ?

    Please help.


  18. Hi,

    I have 1 TB External HD, I would like to create partition 500GB each and make 2nd part as bootable HD. Is it possible ?

    Please help.


  19. When after i mark the partion as active and then try to format fs=fat32 quick
    It says Virtual Disk Error : the volume size is too big.
    Help me please

  20. I am currently running Windows 10 on a PC. I want to be able to dual boot either Windows 10 from my C: drive or Windows 8.1 pro from an external USB connected hard drive. I have Win8.1 _English_x64.iso and a clean NTFS formatted 465GB hard drive. Is this something you can help me with?

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