I have completely messed up my Mac OS X Lion 10.7 on my 2011 Macbook Air (Refer thread : Is there an alternative to downloading Lion from the net?)

Recovery Parition attempts to install from the internet. This is not an option since I have attempted atleast 6 times, It takes 18-20 hours for each iteration and fails somewhere in between because my net connection is not reliable.

What I need to do :

  1. Install Mac OS 10.7 Lion on my MacBook Air

Here is what I have :

  1. InstallESD.dmg file for MAC OS Lion 10.7.4
  2. A PC with Windows 7 32-Bit
  3. 2011 Macbook Air (Without CD Rom Drive)
  4. Disk Utility in the Macbook Air Recovery partition
  6. 16 GB USB Thumb Drive

How do I accomplish this ?

I found this page but the author claims the tutorial is not valid. So how do I burn a Lion DVD / Thumb drive from Windows 7 ?

  • Where is the InstallESD.dmg? on the Windows 7 computer?
    – Jonathan.
    Jul 8, 2012 at 9:31

1 Answer 1


Assuming that the InstallESD.dmg is on the windows 7 computer:

  1. Copy the InstallESD.dmg file onto the USB drive (just copy, not burning etc)
  2. Boot into the MacBook's Recovery Partition.
  3. Plug in the USB drive and open disk utility.
  4. Restore the USB drive using the InstallESD.dmg on the USB drive *
  5. Restart and boot from the USB Drive.

*You might not be able to restore from an image that on the drive being restored. In which case use 2 USB drives (one to copy the InstallESD.dmg from the PC and one to restore it to and boot from) or:

  1. open terminal from the Utilities menu in the recovery partition (on the homescreen).
  2. Use ls /Volumes to find the location of your hard drive and USB drive
  3. Use cp to copy the InstallESD.dmg to you hard drive. (e.g. cp /Volumes/USBDrive/InstallESD.dmg /Volumes/Macintosh\ HD/, where you replace the paths with the ones found in step 2)
  4. Open Disk Utility and restore the USB drive using the InstallESD.dmg on your hard drive, if you can't find your hard drive in the Open dialog, press cmd+shift+g and you can enter the path manually.

Or if your USB CD drive can burn DVDs and you have a DVD, you could use the USB drive to copy from windows and then use the Macbook's Disk Utility to burn the image to the DVD. (or use the DVD to copy from the PC and use the USB drive to boot)


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