How to create a bootable USB drive from an ISO image for UEFI systems

At the time this post is being written, March 2012, at least some UEFI systems don't boot to NTFS USB thumb drives.  These UEFI systems will only boot to FAT32 USB thumb drives.  I have no idea if this will change in the future.  The details of UEFI are outside the scope of what I typically deal with.

There are several utilities for creating a bootable USB drive from an ISO image, but you’ll most likely end up with something formatted with NTFS.  This won’t boot on some UEFI systems.  Instead, right-click on your USB drive and select “Format…”.  Ensure that FAT32 is selected as the file system and click “Start”.  You can also format a drive from the command line using format or diskpart if you like.

If you’re on Windows 8, double-click your ISO image to mount it.  If you’re on earlier versions of Windows, use a 3rd party utility to mount the ISO.  Just search the web and you’ll find options.  Or, burn the ISO to a DVD and then mount it.  Once the ISO is mounted, copy all files and directories over to your newly formatted USB drive by dragging and dropping.  You can also do this from the command line using robocopy or xcopy.

You’ll then have a USB drive which will boot on UEFI systems.  It will also boot on systems which use a BIOS instead.

I hope this saves people some time.  I spent quite a while wondering why I couldn’t get a USB drive to boot on one of my newer systems.

Comments (6)
  1. Uri Miller says:

    Thanks for posting this solution. I've been trying to boot WIN8 installtion from USB flash drive for the past two days without success, I thought i tryed everything…

    Thanks a million

  2. Kelvin Jeffs says:

    I just slipstreamed all of the latest Win8 updates and it pushed the install.wim well over 4GB (The limit of FAT32 file sizes)  No problem, I'll just split the image using DISM or ImageX but no, Windows 8 installation fails when using split images…says it can't find the license file.  Windows 7 installed fine with split images.

    Very annoying!!

  3. Shahnewaz Maqbul Ahmed says:

    I have the same problem as Kelvin Jeffs. What to do now?

  4. santoshs says:

    You can try ISO to USB or UNetbootin. Both apps are freeware and easy to use.…/guidehow-to-create-bootable-usb-drive.html

  5. ripee says:

    To be able to fit your newly-slipstreamed image onto a DVD or 4GB flash drive, you need to convert the install.wim file to install.esd with the following commands:

    dism /Export-Image /SourceImageFile:"C:install.wim" /SourceIndex:1 /DestinationImageFile:"C:install.esd" /Compress:recovery

    dism /Export-Image /SourceImageFile:"C:install.wim" /SourceIndex:2 /DestinationImageFile:"C:install.esd" /Compress:recovery

    Assuming you put your install.wim file in your C drive's root folder. Not that you must run the second one right after the first and it will add index 2 to the file that's created from index 1. The first command will take longer to run than the second.

  6. HostMarcel says:

    or you can use rufus usb tool 🙂 if anyone needs more info on how to make a usb recovery i will help you just leave me a mail at

Comments are closed.

Skip to main content