I have a MacBook Pro with a working BOOTCAMP partition running Windows 8, and a damaged OS X 10.10 beta partition. The problem is that I cannot boot with the OS X partition, and in order to reinstall the OS I have to set a bootable media.

NB: I already tried to make a bootable usb using TransMac with the InstallESD.dmg extracted from the Install OS X Marvericks.app but it doesn't work

  • Can I launch the installation directly from the Windows partition?

  • Is there any other way to make a bootable media?

3 Answers 3


As far as I know, you can't "launch" the installation directly from Windows. From there, you have two choices :

  1. Normally, you should have a recovery partition on your Mac. Boot on this one, you'll be able to repair or reinstall OS X.
  2. Create a bootable USB stick with OS X on it to reinstall your main partition. There are lots of tutorials that show how to create a bootable OS X USB stick on Google, it's pretty easy to find.

Good luck


Here You Go:

Open Command Prompt with administrative permissions. Type the diskpart command and press Enter. Type the list disk command to view a listing of drives connected to your computer and press Enter. Type the select disk command followed the number assigned for the USB flash drive (e.g., select disk 4), and press Enter. Type the clean command and press Enter. Type the convert GPT command and press Enter. Type the create partition primary command and press Enter to complete the task.

Install Transmac trial

Insert the USB drive that you’ll use to fix your installation of OS X. Remember that all the data in the USB will be erased. Make sure you take off any important documents.

Right-click the TransMac software icon and Run as administrator. You’ll be prompted to Enter Key or Run, because we’ll be using it once, click Run.

On the left pane, you’ll see all the Windows PC drives listed, right-click the USB drive you’re intending to use to reinstall Apple’s OS X and click Restore with Disk Image. Use the Restore Disk Image to Drive dialog box to browse for the DMG file with the installation files for Mac OS X Yosemite in this case, and click OK to create a bootable USB of the Operating System. Now wait. Go have a snack. Do your anterior pelvic shift exercises. May take 1-2 hours.

Once your bootable USB installation media is ready, remove it and insert it into your Mac, power it on, holding down the Option key, and select the USB you just created to reinstall Mac OS X.

If you’re having issues trying to create a bootable media, you can get a USB flash drive that comes with Mac OSX ready to install.

  • Welcome to Ask Different and thank you for your answer. :) I'm sure this will be really useful for many users! However, can I suggest you clarify the first paragraph re the actual commands you're using (e.g. diskpart, list disk etc) so that users know exactly what to enter. Basically, we try not to presume that users know what we're talking about when we provide an answer (unless it's clear from the original question that they're familiar with something). Once again, thanks for your contribution. :)
    – Monomeeth
    May 26, 2017 at 22:25

Even if macOS is damaged and the recovery partition is missing, by using the Cmd+R when you power on your Mac while it's connected to Internet (with Ethernet), the Mac will download the recovery partition by itself.

Apple support article on the topic. It should also be possible over wifi.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .