Is it possible to create a bootable USB drive for installing Windows 8 without access to a copy of Windows?

I know I could install a VM and install Windows there, then make the bootable drive and use Bootcamp to actually install that way, but honestly I would rather not have to put the extra software on my system if at all possible.

I checked the Bootcamp documentation and it says I may have the option to "create a windows installation disk" but I don't have that option (unsure why?)

Additional information: USB Key capacity: 1 16gb and 1 30gb OS ver: OSX Mountain Lion Machine: Late 2010 MacBook Air

  • I've been trying to use Disk Utility to perform the usual scan image for restore and then restoring the ISO I downloaded from MSDN and keep running into errors either scanning the image for restoration or just restoring it...
    – bmike
    Oct 29, 2012 at 2:41
  • I'm trying this now. Hopefully it will work: superuser.com/questions/244838/…
    – user28278
    Oct 29, 2012 at 3:52
  • FWIW - Installing Virtual Box, setting the MS dmg to be in the optical drive and installing Windows 8 onto the virtual appliance took less than the 17 minutes between my comment and your comment above. You might come out far ahead just installing into the VM and rolling your installer using the official MS tools.
    – bmike
    Oct 29, 2012 at 4:12
  • Well, I used the info at the link I used and now when I plug in the thumb drive it automatically opens, but it doesn't show up in the boot manager when I reboot with Option.
    – user28278
    Oct 29, 2012 at 4:21
  • 1) Covert IMG to ISO 2) Use bootcamp assistant pocket-lint.com/news/45898/how-to-install-windows-8-on-a-mac Nov 9, 2012 at 4:16

2 Answers 2


This adds on to Django's answer, pointing out how to allow the option for revealing "Create a Windows 7 Installation Disk" in Boot Camp Assistant.

I checked the Bootcamp documentation and it says I may have the option to "create a windows installation disk" but I don't have that option (unsure why?)

Because you cannot see this option, it is most likely because your computer is not supported in Boot Camp Assistant.app's Info.plist. However, that can be quickly changed.

  1. Open a new Terminal window and run sudo nano /Applications/Utilities/Boot\ Camp\ Assistant.app/Contents/Info.plist

  2. Type in your password.

  3. Move with the arrow keys down to the bottom where it says:

(I meant to start with " (<) key (>) USBBootSupportedModels (<) /key (/>), but I don't know how to ignore HTML markup here. If a moderator or someone who knew how could change this, that would be great.


Check for your computer model number in  > About this Mac... > More info... > System Report... in Hardware Overview under Model Identifier. It should be something like

    Model Identifier: iMac10,1

iMac = IM, Mac mini = MM...and your MacBook Air would be MBA. Now, simply take MBA and add it to the numbers after (MacBook Air3,2 to MBA32) without the comma.

Go back to your Terminal prompt and remove the current string part with MBA (you may want to make a note of this somewhere, in case you decide to revert later). Replace it with an identical one that says:

... <string>MBA32</string> ...

(Without the ellipses)

Now save the file by typing Control-O and confirming the WriteOut by pressing the return key (make sure Wrote xx lines appears). Quit and re-open Boot Camp Assistant, and the option should be available!

At this point, you can select your .iso image, as usual (given that you've already converted the .img)

  • From the question: "Using Windows 8 .img file to create a bootable USB thumb drive". Nov 12, 2012 at 0:42
  • @DjangoReinhardt Hey, no hostility intended! :) I was adding on to your answer, at the end, I said "given that you've already converted the .img"
    – Ethan Lee
    Nov 12, 2012 at 1:31
  • Hey, I just did to you what you did to me. shrugs Nov 12, 2012 at 4:19
  • @DjangoReinhardt OK, but I was only suggesting that your answer made a reference to a feature that wasn't accessible for the asker. I've removed the downvote, however, because I feel that the point you made about the .iso conversion is helpful. Also, my answer has been edited, making it more clear that this is the completion to step 2 in your answer.
    – Ethan Lee
    Nov 12, 2012 at 4:29
  • This answer provides the most information. Thanks all. One step of note, when you get to the part where you have to pick the partition to install Windows, there is a partition that Bootcamp creates called BOOTCAMP. Intuition says to install to that partition, however installer throws an error because Bootcamp Assistant is unable to actually create an NTFS partition. Use the installer to format the BOOTCAMP partition, and then you can proceed as normal.
    – user28278
    Nov 13, 2012 at 18:46

It seems Bootcamp Assistant should be able to help you with this (especially as you have a MacBook Air). It odd that it doesn't. Another weird move from Apple. Because of this you may need to do some system editing, as ethanlee16 points out, to convince BA to give you the option of creating a Bootable USB.

Follow his instructions, or if you don't want to go into terminal, follow these instructions.

And then follow these:

First, convert your Windows 8 .img file to an .iso file. You can do this within OSX by following these simple instructions.

Next, just use the new .iso image with Bootcamp Assistant to create a bootable USB drive with Windows 8 on it. These instructions (as posted by Alexandr Mazanov in the comments) do a great job of explaining what to do.

No need for Windows or any VMWare. Good luck!

  • From the question: "I checked the Bootcamp documentation and it says I may have the option to "create a windows installation disk" but I don't have that option (unsure why?)"
    – Ethan Lee
    Nov 11, 2012 at 5:20

You must log in to answer this question.