I'm trying to create a Windows 7 installation USB (for use on a PC) from OS X.

I've tried following these instructions from a similar question on superuser:

  • Insert the USB flash drive and run the command diskutil list to find out the disk name, we'll use /dev/disk1 as an example
  • Now unmount the disk using diskutil unmountDisk /dev/disk1
  • dd if=/path/to/Win7.iso of=/dev/disk1 bs=8192

But the instructions don't work. When I insert the created USB drive into my PC and try to boot from it, I get this message:

Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key

What am I missing?

5 Answers 5


Turns out OS X Lion ships with Boot Camp 4.0, the coolest feature of which appears to be the ability to create install USBs.


I hope I am not offending you, but this issue may have something to do with your level of understanding of what that terminal command actually does.

You can't just copy and paste the command :

dd if=/path/to/Win7.iso of=/dev/disk1 bs=8192

.. and expect that to work.

You need to change the above command to point to the actual location of your "Win7.iso" file (if that is what it's named).


Say I have a file called "windo7.iso" and it's currently located on my desktop, then the command that you should be using is :

dd if=~/Desktop/windo7.iso of=/dev/disk1 bs=8192

Hope this helps.

  • 4
    Yes, I am aware, and have been entering the command with the correct path.
    – rubergly
    Aug 15, 2011 at 8:51

I've edited the Info.plist of Boot Camp to be able (https://www.youtube.com/watch?v=rR5KZnRqcxg) If you have a DVD-ROM try http://support.apple.com/en-us/HT203909


After dd, you should check if your new partitions on the USB device are marked as active. Do so using the fdisk utitlity.


Right after turning on your PC press Del to enter Bios Setup and make sure that USB listed first in Boot Priority menu.

  • 1
    I was selecting the USB drive as the boot device; this wasn't the problem.
    – rubergly
    Aug 16, 2011 at 5:37
  • 2
    This is also pretty inaccurate since the key to enter Bios setup depends heavily on the PC manufacturer.
    – rubergly
    Aug 16, 2011 at 18:01
  • 1
    That's true for a laptop, but for PC desktop station i can't remember any case where it was other then Del
    – Serith
    Aug 19, 2011 at 16:21

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