This tutorial is useful to you only if you have an old Intel MacBook Pro WITHOUT the optical drive.

People who have replaced their SuperDrive in their non-Retina MacBook Pros (before 2012) with an extra hard drive may find it troublesome and annoying to install Windows using external methods. People whose SuperDrives are broken are … just … sad.

And I’m one of them.

The Problem:

  • Burning the Windows ISO to DVD and booting using a non-Apple external DVD drive will have you stuck at a black screen with blinking white cursor.
  • Creating the bootable Windows install USB with another MacBook Air or Retina MacBook Pro or with “hacked” Boot Camp Asssistant will have you successfully create the Boot Camp partition and boot into the install drive, but it will tell you this:

The Reason:

Intel Macs have a GPT (GUID Partition Table) and use the EFI (Extensible Firmware Interface). Booting/installing Windows on Macs use a more-troublesome-than-useful mechanism called Hybrid-MBR. The GPT and an “emulated” MBR (Master Boot Record) both exist on the same drive. The Hybrid-MBR works together with an emulated BIOS to support booting Windows. Now that Windows works perfectly on EFI + GPT, there’s no point emulating MBR and BIOS because it just complicates.

According to Wikipedia, “In a GPT, the first sector of the disk is reserved for a “protective MBR” such that booting a BIOS-based computer from a GPT disk is supported…”

According to Rod Smith, “A hybrid MBR is a variant on the normal protective MBR”.

A “hacked” Boot Camp Assistant can create and boot the Windows USB install disk, but this hack cannot extend to the firmware level, creating this bug in which USB boot methods (in absence of the DVD drive) don’t start the emulated BIOS, leaving Windows a EFI + MBR environment to which Windows cannot install.

The Solution:

Your warranty is possibly void.
I am not responsible for your computer exploding,
people falling from the sky,
thermonuclear war,
or you getting arrested by the FBI
for modifying your partition table.
YOU are choosing to read this tutorial,
and if you point the finger at me for messing up your Mac,
I will laugh at you.

The following solution does not involve wiping or reformatting your disk. But if you care, back up your disk first, because I’m not responsible for your actions.

  1. Get GPT fdisk from its SourceForge. This is a cross-platform open-source disk partitioning tool. You can use it in Linux or Windows but I’ll show you how to do it in Mac OS X.
  2. After installing gdisk, open your Terminal and become SuperUser. The commands you type are red and underlined. (Make sure you have set a root password)
    localhost:~ iHackMyStuff$ su
  3. Opengdisk.
    sh-3.2# gdisk
    GPT fdisk (gdisk) version 0.8.10
  4. Choose the disk you’re working with (/dev/disk0 if it’s the disk you’re operating in).
    Type device filename, or press <Enter> to exit: /dev/disk0
    Warning: Devices opened with shared lock will not have their
    partition table automatically reloaded!
    Partition table scan:
     MBR: hybrid
     BSD: not present
     APM: not present
     GPT: present
    Found valid GPT with hybrid MBR; using GPT.
  5. Enter the experts’ advanced menu.
    Command (? for help): x
  6. Create a new protectiveMBR.
    Expert command (? for help): n
  7. Write table to disk and exit.
    Expert command (? for help): w
  8. Confirm. (This will not reformat your disk or wipe your data. It will justmodify a part of your partition table.)
    Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
    Do you want to proceed? (Y/N): y
  9. Boot from your Windows usb installer and install Windows like you normally would, only without the optical drive! If you don’t have a MacBook Air or Retina MBP near you, then check out how to enable Boot Camp Assistant to create Windows USB install disk.
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