How To Install Windows 7 To USB External Hard Drive [Must Read]

While one can install Windows 7 from an external hard drive or USB, one can’t install the same to an external hard drive. For all those users waiting for a workaround to install Vista, Windows 7 and Windows Server 2008 R2 to an external hard drive, here is a complete solution.

Windows 7 SP1

Even though Windows recognizes and displays the USB hard drive in the installation screen, it doesn’t allow you install Windows on the same. So, if you want to install Windows 7 on an external hard drive you need to follow the steps given below.

Install Windows 7 to an USB external hard drive

The procedure is simple but you need to install Windows Automated Installation Kit first to get some files. We would like to thank fujianabc @ boot-land forum for this workaround.


# An external hard drive formatted with NTFS

# Windows 7 installation files (if you have Windows 7 ISO use Virtual Clone Drive freeware to mount it)

# Windows Automated Installation Kit (free download from Microsoft)


NOTE: Make sure that you have a minimum of 15 GB free space on your external hard drive before starting the procedure. Although we are not going to delete the contents of external hard drive, we recommend backing up your external hard drive contents before trying this guide.


1. Create two folders named Windows Files and WAIK Files on your desktop or any other drive which has a minimum of 5 GB free space.

install windows 7 to an usb external hard drive

2. Download the ZIP file from here and extract the contents to WAIK Files folder. Before starting the actual installation procedure, you need to have three files: Bcdboot.exe, Bootsect.exe and Imgex.exe. These files can only be obtained by installing Windows Automated Installation Kit for Windows 7 on your Windows PC. After installing WAIK, simply search for these files in the Windows installation drive to get them. Once you have these three files, copy them to WAIK Files folder that you have created in the above step.

Install Windows 7 to an USB external hard drive10

3. Copy all the contents of Windows 7 installation DVD to the Windows Files folder.


4. The next step is to run Installer.cmd file as Administrator (Right-click on installer.cmd and select run as administrator). In the first screen, you will be asked to press Enter to continue.

Install Windows 7 to an USB external hard drive15

5. Press Enter key to browse to the install.wim file present in the Windows Files folder. The Install.wim file can be found under Sources folder (Windows Files/ Sources/ install.wim).

Install Windows 7 to USB external hard drive1

install windows 7 to usb hard drive

6. Now, you need to select the Windows 7 edition that you want to install on external hard drive. You can select the edition by entering the index number shown in the screen. For example, type “5″ (without quote) and hit Enter key to select Ultimate edition.

Install Windows 7 to an USB external hard drive2

7. The next step is to enter your External drive’s drive letter. Enter the drive letter (ex: L) and press Enter key.

Install Windows 7 to an USB external hard drive3

8. Now, type in the drive letter of your ACTIVE partition and hit Enter key. Generally “C” is the active partition. You can find the active partition by opening Windows Disk Management tool (type diskmgmt.msc in Start menu search area and hit enter to launch it).

Install Windows 7 to an USB external hard drive4

install windows 7 to usb external disk

9. Finally, the installer will ask you the drive letter that you have entered to install Windows 7 is a USB hard drive or not. As you are installing Windows 7 to an external hard drive simply type “Y” without quote and press Enter key.

Install Windows 7 to an USB external hard drive5

Finally click Enter key again to start extracting the Install.wim files. This might take a few minutes. Once done, you will be asked to reboot your PC to continue the normal Windows 7 installation procedure.

Install Windows 7 to an USB external hard drive7

Install Windows 7 to an USB external hard drive9

10. Reboot your PC and follow the usual Windows 7 installation procedure to complete Windows 7 installation on external hard drive. Your PC will be restarted twice or thrice during installation.


Please note that the installation procedure might be slower as you are installing Windows 7 to an external hard drive.


11. Once done with the installation, you are good to go. You can install all drivers and other software to start using the best Windows version on your PC.


Note: We have tested this method to install x86 flavor of Windows 7 to Seagate USB external hard drive. But should work fine with x64 as well. Users who would like to carry Windows 7 on a USB flash drive can follow our how to carry Windows 7 on USB flash drive guide.


  1. RIN says

    Why is mine saying wincmd cannot be found?

    Also it is not finding setwimpath??

    How can I fix these?

  2. step 8 says

    Step 8 isn’t fully clear. Basically, you want to use the same drive letter as your USB drive. E.g: if install on usb E:, then you want E: in the step not C: otherwise you brick your system. ;)

    The metod isn’t work for 100%. On some hw just doesn’t work.

  3. says

    ——–DOES NOT WORK——–

    ——–DOES NOT WORK——–

  4. Daniel says

    Has anyone that got to the install and got ‘can’t install to USB drive’ managed to get it working?

  5. Pissed says

    What is the point of this if i still need to have my original boot drive in my pc in order to boot from the external usb?

  6. admin says

    I don’t think it’s possible when you have installed Windows 7 on external using the above mentioned method.

  7. Jack says

    Is there away to remove the Windows 7 option from windows boot manager after the install is complete? so my computer just starts like it used to?

  8. Pete Ash says

    One other thing; there were 3 versions of Imagex.exe on my laptop (for some reason), one of them is the 64-bit version and the other is the 32-bit version. Just ensure you have the correct version for your OS inside your WAIK folder. They can be found at C:\Program Files\Windows AIK\Tools\x86 and C:\Program Files\Windows AIK\Tools\amd64 respectively. So far so good……..

  9. Pete Ash says

    The file “Imgex.exe” is actually “Imagex.exe” : Note the “A”. This is real confusing unless you search for the answer as to why this can’t be found in the WAIK installation. Thanks though for a great article.

  10. Rumanoid says

    HELP PLEASE!!!!!
    I used windows xp to run the script, and at the end I got some errors. While trying to boot for the first time it installs just fine, but when i reboot to just run windows, it will stop halfway loading the windows logo, flash a blue screen and then reboot. I filmed it and watched in slow motion and it says something about new hardware failure
    PLEASE HELP!!!!!

  11. Josh Wiggins says

    Im on step five and im using Windows 8 64bit os and whenever i click my install.wim file it says this app can not run on your pc ?

  12. Snoopy says

    Select the install.wim from your Windows Installation DVD or image, but not from the “Windows Files” folder you’ve created previously. At least, that has worked for me.

  13. Hugh Perkins says

    I needed to mark the partition active (using diskpart), and use bootsect /nt60 [/mbr] on my usb drive letter, before it would boot from the usb.

    diskpart is on any Windows 7. bootsect is one of the files that is copied into Waik Files folder.

  14. shubham says

    Hello I want some help. I tried a lot to install windows 7 to My external HARD DRIVE but I have not succeeded yet . I have done the whole procedure correctly but in the end , at the time of installing windows 7 I got message that “windows cannot be install to this disk . setup does not support configuration of or installation to the disks connected through USB or IEEE 1394 port”. please help me out of this error.

  15. Kiko says

    Hello! While trying to do this, in the image number, there are no images available (to choose which version of windows I want to install).
    Does anyone else had this problem? Any ideas in how to solve it?
    Thank you for your help!

    Best regards,

  16. suresh says

    what is the diff between drive letter of ext hd and drive letter of active partition(step 7 and step 8) is thedrive letter of active partition the drive in which win 7 is alredy installed in internal hd?

  17. Haitham Said says

    For those facing Blue screen.
    It means that the new hardware (for the usb hard disk loptop) were undefined so.
    Before going through the previous steps make the following:
    1- The WAIK folder and Windows Folder save them in any partition of the usb had disk
    Then go on with the magic steps at the end before restarting the computer
    1- Remove the hard disk and attach it to the original Laptop
    2- Start the original laptop and it will start the installation windows and begin to identify the hardware.
    I wish i have made something good

  18. Raymond says

    Hi! everything was fine until i reboot..
    After reboot.. Starting Windows.. Suddenly Blue Screen “A problem has been detected and windows has been shut down to prevent damage to your computer”


  19. Tony Prodger says

    I have followed all the steps (had to find and download some of the files from other sources). Am using windows 7 and when I try to install Windows 7 (64) although the external drive is shown as an option, when I choose it I am informed that:

    windows cannot be installed to this disk. Setup oes not support configuration etc..

    Am I doing something wrong?

    many thanks

    Tony Prodger

  20. Burak says

    I have a problem with this installer
    Everything is going well until it finishes copying files when it finishes it says this message “Failure when attempting to copy boot files ” I did everything as ordered but i’m stuck here

  21. Suraj Murudkar says

    Guys, it works great and very effectively. I have installed Windows 7 in my new 500 GB External HDD and its going very smoothly. Even the the links here given are working and easy to download, thanks to person whoever have made this page, Thanks alot :)

  22. Jeremy says

    I got to step 10, but when I try to restart the computer to install the OS, it won’t start the installer.

  23. Eric Beyer says

    I get to step 10 without errors. My green screen looks exactly the same as yours. But when I reset my PC, it boots only to my main HD. I cannot boot this drive on this or another PC I have to finish the install. What am I doing wrong?

  24. Deendayal Sundaria says

    I have installed windows 7 on my external hard disk and it is working fine with my acer laptop but my another dell laptop on boot displays blue screen.

    Please help me to fix this issue.

  25. Axedall says

    I am having a problem where in step 5 when I select the install.wim file, I get a message saying “this app can’t run on your pc”. I am running windows 8 on an x64 machine. I copied the WAIK files from the x64 directories (ia64\Bcdboot.exe; tools\ia64\imagex.exe) except for Bootsect.exe which only had a amd64 and x86 folder version so I used the one from amd64)

    Has anyone else had this problem and/or know of a solution to it?

  26. Kevin O says

    i tried to run installer as admin and i found the “install.wim” file but it tells me:

    ” The image file C:\Users\Kevin\Desktop\WAIK Files\imagex.exe is valid, but is for a machine type other than the current machine.”


  27. Ja says

    Idiot. Step 8 is not C: it’s the boot partition of your flash drive, I’ve fcked up my system…

  28. Libor says

    Hi all!

    Anyone else is expecting error at step 7? i go all needed stuff, all if fine, disk set as primary active 25GB but when i set the LETTER of USB DRIVE, press Enter….and its gone,it fails with no error, just disappears. Anyone any ideas? yes i am running it as Admin..

  29. maik says

    hi, very good tutorial, but, can i use thi procces with a windows 7 lite? sorry for my english ^^

  30. Sofia says

    I followed all the steps until 9, but then shows me “ERROR: The system can not find the key or registry value specified”
    ERROR-Failed to get target OS drive letter info from registry.
    Script failed.
    When I go to boot from cd, selecting where I want to install shows no drivers.

  31. Morocco says

    Heads up everyone if you experience my problem, I solved it because I missed the “Run installer.cmd” as admin.

  32. Morocco says

    Hello, I am through to the step where I select my active partition. It is “C:” for my computer, yet when I enter “C:” or “C” it states it is an unwritable disc and to enter a new letter. What does this mean?

  33. Jeffrey says

    I’ve completed all the steps as shown but when I try to boot from the drive I’ve put the os on it needs a boot loader/mgr. Why?

  34. sunny says

    hi i have done all the above procedure using a 8 gb pen drive the hole procedure is done as u say but when i am restarting my PC nothing happened its start normally or when i start using boot option and c house pen drive ctl+alt+del error has come what should i do can i upgrade my pen drive or there is ant other way i want to use windows in my pen drive

  35. Ricardo Quesada says

    Thanks for all this help, I just made it and works fine.
    The only one problem I’m having is when trying to install .Net framework 4 or Sql Server (tools that I’ll need in my image), it is just crashing and don’t know why… Do you have any idea that could help me with this?? I’ll really appreciate that!

    Thanks in advance.

  36. Bhen says

    Hi i did everything and it was ok, but when i try to boot it on the other laptop it say windows operating system couldn’t be found something like that , how can i fix this? i’m using 32gb flash disk, because my internal hard disk is having a problem and i can yet afford to buy new Hard disk, thats why i want to use my 32 gb flash drive for the mean time.

  37. Jaime says

    Well, thanks for the suggestions.
    This procedure enabled me to rescue a hard disk that was not booting. It was necessary to boot my broken PC from an external USB hard disk previously prepared from another computer. I want to clarify general aspects and some variations that were necessary in my case in order to make everything work fine.

    First: The files needed to copy into the “WAIK Files” folder can be found from various sites in the Internet under the name of “NT6.X_fast_installer”

    Second: The software: Automated Installation Kit (AIT) must be downloaded from the Microsoft web site, as it comes in ISO format it is necessary to burn it into a DVD in order to install it later.

    Third: In my case, after I ran the “installer.cmd” file and I finished up loading Windows 7 in my external hard disk, it did not boot and I could not continue with the Windows installation. I repeated this process several times without having success.

    SOLUTION: Make a quick format to the external USB hard disk and then use on of the multiple procedures found on YouTube to make a boot from an external USB memory. Apply it to the external USB hard disk, I used a simple software called “WiNToBootic.exe” that left my external hard disk booting perfectly. After this, go into the external hard disk and erase all the files copied, the only files left are the hidden boot ones. Then, continue normally with the process of running the “installer.cmd” file as an administrator and all the other steps described in this blog.

    In the end, when the boot from the external usb hard disk is required to finish the windows installation, unplug the disk and connect it to the PC in which you wish to recover your lost information. The external disk will boot up normally to finish the windows installation, then go to the broken disk to rescue your lost information.

    Thanks for all you comments and I hope it works for you.

  38. keith says

    this is not working. don’t tell me nothing. I went through the steps. Don’t know where it partioned but not on my external hardrive. rebooted and tried to install and same dam error shown from the beginning of step 1. this is stupid. WILL NOT LET ME INSTALL WINDOWS TO MY EXTERNAL HARD DRIVE…

  39. hezron93 says

    where is the zip files to be inserted to the WAIK folder? cant find it in the link given.. :((

  40. Kathy says

    I followed all the steps, but when i run the windows intaller, it still says me that windows cannot be installed in am usb :S, after i do the first boot nothing happened, i dont know what to do.

  41. Eugene says

    Hi , thnx for info, but I have a question. If I want to boot from usb external hdd. for example if I don’t want to use my hdd in laptop at all. I need just create for example, small active partition on usb hdd , and primary. And in step when we choosing letters use them?

  42. Ken Frey says

    I went through all the steps but he installation doesn’t start after the reboot. When I start the installation from either the Windows Files folder or a DVD it still says that I can’t install on a USB drive.

    I’m using a hard drive in an external enclosure that has it’s own C drive as it’s boot drive. As my external drive it is the F: drive. My only thought was that in step 8 it is asking for the Active partition. I chose the F: drive. My concern was that if I chose C: (the active and boot partition for my laptop) that it would compromise my laptop. Thoughts/ideas?

  43. aahhhhhh says

    This ruined my OS. I got to step ten just fine (hadn’t installed windows 7 yet) rebooted after the WAIK green screen part then when my PC tried to boot up my standard OS, it fails. It thinks its trying to boot windows 7 and gets confused and restarts again and again. I checked the boot sequence in the BIOS to make sure its not trying to boot from the external and even unplugged the external. I can’t even get into safe mode or anything.

  44. Arms Longo says

    May I add: you may have to use the imagex.exe file from a different architecture than you would think: I am going thru this procedure for a Thinkpad with Intel core i5– and it only worked with the imagex.exe file from the “AMD” folder in the waik files.

  45. EM says

    Congratulations, I use this procedure and all is ok… thank you for that help about “How To Install Windows 7 To USB External Hard Drive [Must Read]” Felicitaciones por este procedimiento para instalar Windows 7 en disco duro externo. Todo muy bien. Gracias por todo.

  46. TOBY.G says

    my computer does not restart and when i restart my computer with the USB all i get when it is starting windows is a blue screen witch say that there is a error

  47. PRAJWAL says











  48. Sulpicio says

    i managed to make a solution with the no grldr problem. now i facing with the Blue Screen! after it boots and loads windows 7 logo it hang up and blue screen shows. i read that some solutions is to disable SATA from bios, but when i check my bios, i did not found any SATA configuration. help please

  49. Sulpicio says

    Hello, i successfully installed my windows 7 to external Western Digital 500 gb. but when i boot from my Sony Vaio, it says “no: grldr”. so i troubleshoot it using my PC, the PC boots from the external HD but then works fine.. how to fix the problem when i boot my external HDD to the laptop? please help..

  50. mahir says

    hi there every thing went really smooth until this error showed_up “error occurred when loading the registry ” then “press anykey to exit” . any ideas

  51. Travis Stein says

    Was pulling my hair out until I saw the .jpg in step 2 over “imgex” not being “imagex”. Please correct this! :D

  52. Friggi says

    I though I followed then instruction 100% but when I try to boot up from USB, then LP boots up like normal, just a bit slower!? Any idea?

  53. anonymouse says

    bcdboot.exe and imag.exe can be obtained here:

    bootsect.exe is in your windows installation files! after extracting the installation files from the iso as instructed, open the “boot” folder and you’ll see bootsect.exe. make a copy of it and put it in the waik folder and you’re ready to start!

  54. Brandon says

    Everything worked great up to step 10, it finished and said hit any key to exit, did not ask to reboot to finish installation. When I rebooted myself and selected the external as the boot location, it simply loads the operating system on the computer, is there something else I am missing

  55. Deme says

    I’m trying to do this on a Mac, All works up until booting from the USB at which point I get the Blue screen of Death (BSOD). I saw some people mention disabling the SATA in the BIOS but the mac has no BIOS :( has anyone figured out an alternative to this or is there a way to inject hacked drivers to the windows startup so that it can bypass the SATA controller?

    Any help appreciated.

  56. 12344321 says

    when i try to select active partition it tells me that the partition is not writable, please help!

  57. Ryan says

    I got this to work as well. Even on an older laptop with a Pentium M. It’s slow but works well!

  58. David Williams says

    Thanks for this shit. I did everything, it rebooted and logged into windows normal and now my pc doesnt detect USB devices and there is no solution. Fuck you

  59. Draco says

    How long dose it take to setup after you restart for some reason its taking varry long its setup is installing devices and its at 27% and its ben slowly moving so far maybe 4hrs or more like 20min for 1%

  60. Ganesh says

    I Have Install win 7 32 Bit in may Ex HDD but this is the use only one computer, i will be connect another computer not working win 7 in External HDD,
    please Give me Solution used in any computer in external HDD win 7 32 Bit.

  61. Jesus says


    I have done this and all runs perfectly with the exception of the virtual memory as the paging size resets itself to 0 every time I restart my system, so anything that uses a lot of memory cannot run.

    Any ideas on how to fix this problem?

  62. SuVuTi says

    It works with 64 bit windows also. runs a little slower than having an actual HDD but surprisingly fast for a portable HDD. just follow the steps and make sure everything is good.
    You can also input this within the cmd window after restart and install so that you can run on any pc=

    \windows\system32\sysprep\sysprep.exe /loobe /generalize /shutdown

    (make sure to put the spaces in exactly where I have placed them {between [sysprep.exe, /oobe, /generalize and /shutdown]})

  63. Carbon says

    Hey i completed every step and even booted it succeesfully on the laptop i did the steps with, but when i try it on other computers, it says “BOOTMGR is missing press ctrl+alt+del to restart…” anyone able to explain how i get around this?

  64. KP says

    Can someone help me fix the corrupted boot sector of my
    hard drive? I installed the win7 pro onto my WD hard drive with the helpb of this document but after a windows update I cannot boot it anymore.

  65. Shen YL says

    I have install Win7 according to your instruction on an ASUS MB, HP Notebook, LG Notebook. I was able to install it on my Fujitsu netbook, only if I set the SATA to IDE mode. Is there a way to slip in the AMD SATA Controller? Your approach bypass the F6 in phase I of Windows 7 installation, where one could load the special storage drivers. Please help, I tried injecting the drivers into the BOOT.WIM and INSTALL.WIM, but always get the BSOD during step 2 of the Installation.

  66. Grom says

    The link to downloading the files into the “WAIK Files” folder doesn’t exist can you please re-upload the zip and repair the link please? Can always email me the zip file if you can. Thanks!

  67. KP says

    I have installed Win7 Pro and Ultimate a couple of times according to the original instructions (1.) .
    It worked perfectly. The problem is that installing some applications, windows updates or even uninstalling applications will cause BCOD or failure to boot. I cannot figure out how to fix these problems.
    So I reinstall Win7…..???????!!!!!!!

  68. Daniel :) says

    I can’t find Imagex.exe on my computer. After I installed WAIK I found Bcdboot.exe and Bootsect.exe but Imagex.exe could not be found. PLS HELP

  69. R?mak???a says

    For people reporting broken link to ZIP file from step 2:

    1. Google for “Windows Vista/2008/7/2008 R2 Fast Installer” or for “NT6.X_fast_installer_100219.7z”


    2. Try one of the following links:


    For people reporting broken downloads of Windows Automated Installation Kit:
    the correct md5 of KB3AIK_EN.iso is 1e73b24a89eceab9d50585b92db5482f.


  70. hagen says

    My usb drive letter was F:
    So I chose:

    driveletter os-partition F:
    driveletter bootpartiotion F:
    usbdisk: yes
    last question I didin’t make a change

    This installation is perfectly working on my dektop
    But is not working on my laptop

    I started with testing on my laptop (BSOD)
    Then I plugged it in my desktop and all went well.

    I still can’t use it on my laptop
    any suggestions?

  71. Himanshu says

    after completion of all above steps getting below error when booting on USB SEAGATE GO FLEX HDD

    A Disk Read Error Occurred
    Press CLT + ALT + DEL to restart

    can n e 1 help me out this….

  72. Joe! says

    I have a laptop that has a password protected BIOS. I wanted to format and install windows 7 from USB however with the BIOS locked i couldn’t boot from my USB without taking apart the entire laptop to get to the battery to reset it. After reading this i simply removed the HD from my laptop and used an adapter that made it USB accessible (USB 2.0 TO SATA/IDE). Followed the directions and when time came to reboot i just removed the HD and put it back into the laptop and started it up. LOW AND BEHOLD it booted right into installation and now everything works fine. THANKS AGAIN FOR THIS TUTORIAL!

  73. Nikola says

    Can some one make WORKING video tutorial by followin all steps from here ? Thanks

  74. Armin says

    sry for myenglish

    hi, i do this with windows 8 and working, i use windows7 ultimate x64 and i install win8 32bit to seagate expansion 320gb. imagex.exe[find in my friend pc,i think its for win vista] bcdboot.exe[find in win7 drive C: ] bootsect.exe[find in win7 enterprise dvd] in step 10 i restart my laptop and after rebooting its boot to win 7 i restart again and boot win8 and do install progress until chose partition and close setup, rebooting system and boot from my hdd, win8 coming and so nice :D i play pinball in win8 and its amazing. i shout down win8 and disconnect my hdd, turn o my laptop and see blue screen say need usb or disk, i put win7 disk and boot this and use system recover, automatic find problem and fix, rebooting and boot to my win7 but now my microsoft essential security say windows did not pass genune validation, and see under screen in my background this copy of windows is not genuine. this is good have OS on portable hdd but lost your win on internal hdd, its should have a boot menu to chose..

  75. Marki says

    Hi. when i restart the computer it says error starting system on usb.
    what do i do

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