Because OS X Mountain Lion is downloadable software, it does not include a physical installer, typically a bootable DVD or USB drive. For most Mac users, installing Mac OS X on a removable media (DVD or flash drive) when installing cleanly on the boot drive is a must.
Apr 22, 2012 Here's how to make a bootable USB drive or DVD, just like one you'd have back in the good old days. Apple OS X Lion: How To Create Bootable Disk Image. By Josh Windisch. OS X Mountain Lion.
This tutorial guides you through the process of creating the OS X Mountain Lion installer on DVD or USB.
Although Apple ended support for OS X Mountain Lion in August 2016, it is still available for purchase at the Apple Store. Purchasing will generate the download code for you to import into the Mac App Store when downloading the software.
How to create OS X Mountain Lion installer on DVD or USB
- What you need
- Locate the installation of Mountain Lion image
- Burn the bootable DVD of the Lion X Mountain Lion installer
- Copy the installer Lion X Mountain Lion to the USB can boot
- Delete and format USB
- Copy the InstallESD.dmg file to the flash drive
What you need
Picture 1 Create a bootable copy of the OS X Mountain Lion installer download this picture HERE
You need a dual layer DVD (DVD with double sided recording) and a disc or USB drive. DVD dual layer has two layers, increasing the available recording space to about 8.5GB. The OS X Mountain Lion installer is just too big a thing to match the standard DVD. DVD dual layer is available wherever standard DVDs are sold. If your Mac doesn't have an integrated SuperDrive, use an external DVD burning tool.
You can also use a USB flash drive with at least 5GB capacity (8GB and 16GB are available sizes) as a bootable medium.
Download a copy of OS X Mountain Lion that you must purchase at Apple Store online and download it from the Mac App Store. It is saved in the Applications folder on the Mac. This file is called Install OS X Mountain Lion .
You must create a bootable copy of the installer before you install Mountain Lion, because the setup process will delete the files you need to create a bootable copy of the installer.
Locate the installation of Mountain Lion image
Picture 2 Create a bootable copy of the OS X Mountain Lion installer download this picture HERE
The installation of Mountain Lion that you need to create a bootable DVD or USB drive is contained in the Install OS X Mountain Lion file that you downloaded from the Mac App Store.
Because the image is contained in the downloaded file, copy it to the desktop to create an image that can be booted as easily as possible.
1. Open the Finder window and go to the Applications folder (/ Applications).
2. Scroll through the list of files and find the file called Install OS X Mountain Lion .
3. Right-click the Install OS X Mountain Lion file and select Show Package Contents from the pop-up menu.
4. Open the Contents folder and then open the SharedSupport folder . You will see a file called InstallESD.dmg.
5. Right-click the InstallESD.dmg file and select Copy InstallESD.dmg from the pop-up menu.
6. Close the Finder window and return to the desktop.
7. Right-click an empty area on the desktop and select Paste Item from the pop-up menu.
Pasting an item into the desktop takes some time, so be patient.
When the process is finished, you have a copy of the InstallESD.dmg file that you need to create a bootable copy on the desktop.
Burn the bootable DVD of the Lion X Mountain Lion installer
Picture 3 Create a bootable copy of the OS X Mountain Lion installer download this picture HERE
With the Mountain Lion InstallESD.dmg file copied to the desktop, you're ready to burn the installer bootable DVD.
1. Insert a blank DVD disc into the Mac's optical drive.
2. If a message asks you what to do with the blank DVD, click the Ignore button . If the Mac is set to automatically launch an application related to DVD, when you insert the DVD, exit the application.
3. Launch Disk Utility, located in / Applications / Utilities.
4. Click the Burn icon , located in the top right corner of the Disk Utility window.
5. Select the InstallESD.dmg file you copied to the desktop.
6. Click the Burn button .
7. Put a blank DVD in the Mac's optical drive and click the Burn button again to create a bootable DVD containing OS X Mountain Lion.
8. When the burn is complete, remove the DVD, add the label and store the DVD in a safe location.
Copy the installer Lion X Mountain Lion to the USB can boot
Picture 4 Create a bootable copy of the OS X Mountain Lion installer download this picture HERE
If you can't burn DVDs, you can use a bootable USB drive. Create a bootable copy of Mountain Lion on a hard drive. All you need is the InstallESD.dmg file that you copied to the desktop and flash drive.
Delete and format USB
1. Insert the USB into the USB port of the Mac.
2. Launch Disk Utility, located in / Applications / Utilities.
3. In the Disk Utility window open, scroll through the list of devices in the left panel and select your USB device. It can be listed with multiple volume names. Do not select the volume name. Instead, choose the top-level name, usually the device's name, such as 16GB SanDisk Ultra .
4. Click the Partition tab .
5. From the Partition Layout drop-down menu , select 1 Partition .
6. Click the Options button .
Mountain Lion Facts
7. Make sure that the GUID Partition Table is selected from the list of available partition schemes. Click OK. All data on the USB will be deleted.
8. Click the Apply button .
9. Disk Utility requires you to confirm that you want to partition the USB device. Click the Partition button .
USB device deleted and partition. When that process is complete, the flash drive is ready for you to copy the InstallESD.dmg file.
Copy the InstallESD.dmg file to the flash drive
1. Make sure the USB device is selected in the device list in Disk Utility. Do not select the volume name but select the device name
2. Click the Restore tab .
3. Drag the InstallESD.dmg item from the device list into the Source field . It will be near the bottom of Disk Utility's device list. You may need to scroll down to find it.
4. Drag the volume name of the USB device from the device list to the Destination field .
5. Some versions of Disk Utility may include a box labeled Erase Destination. If you fall into this situation, make sure this box is selected.
6. Click Restore.
7. Disk Utility asks you to confirm that you want to perform a restore, delete all information on the destination drive. Click Erase.
8. If Disk Utility requires an admin password, provide the information and click OK.
Disk Utility copies InstallESD.dmg data to USB device. When the process is complete, you will have a bootable copy of the OS X Mountain Lion installer ready to use.
Hope you are succesful.
Happy Mountain Lion Day! Now that you have downloaded the 4.34GB installer, you may want to install Mountain Lion on more than one of your personal machines. Do you really need to wait 45 minutes or more for each one? Absolutely not! Just make your own bootable install disk using our handy tutorial.
We have instructions for those of us who just want to get it done—using the donation-ware Lion Diskmaker app—as well as those that don't mind a little extra clicking to do it yourself.
Important warning: the OS X installer will delete the necessary file needed to make your own install disk once it runs. Therefore, you need to either make a copy of the installer outside of the Applications folder or make your install disk before upgrading.
Got it? Good—let's get started.
Here's what you need:
- An 8GB or larger USB flash drive, other external disk, or 4.7GB DVD-R
- Mountain Lion installer app downloaded from the Mac App Store
- Optional:Lion Diskmaker app
We recommend a USB flash drive for your backup installer; they're cheap and easy to store and transport. Other external drives will also work, but make sure the type works with all your Macs—USB is the most universal. You can also burn the installer to a DVD-R, but booting and running the installer from an optical disc is s-l-o-w.
There's an app for that
If you find digging in to bundles and using Disk Utility to be tedious or bothersome, you can thank developer Guillaume Gète for making Lion Diskmaker. His app automates the process of making a bootable install disk for both Lion and Mountain Lion—just run the app and let it do its thing.
(Why not rename the app to something more generic like 'OS X Diskmaker'? Gète says he just likes the existing name better, and besides, it's less likely to catch the ire of Apple's lawyers.)
Just download the Lion Diskmaker app, unzip it, and run it. You'll basically need to click four buttons: '10.8 Mountain Lion,' 'Use this copy,' 'Create a boot disk,' and, if you're using a USB flash drive as recommended, 'An 8 GB USB thumb drive.' It's really that simple; Lion Diskmaker takes care of the rest. The process will take about 30 minutes or so using USB 2.0 (it should be faster if you have a USB 3.0-compatible flash drive and newer Mac).
Still easy enough for the DIY-er
Burn Dmg To Usb Bootable
If you like doing things yourself, however, the process is still pretty straightforward for any user comfortable with right-clicking and drag-and-drop.
Start by right-clicking (or control-clicking) on the 'Install OS X Mountain Lion' app, which should be in your main 'Applications' folder after downloading. Navigate to Contents > Shared Support, and you should see a disk image called 'InstallESD.dmg.' We will restore this disk image to our flash drive (or other disk) using Disk Utlity.
Then launch Disk Utility. If you're using a USB flash drive or other external disk, you'll need to make sure it's formatted as 'Mac OS Extended (Journaled).' Under the partition options, also make sure the partition type is set to 'GUID Partition Table,' otherwise it won't be able to boot an Intel-based Mac.
Create Bootable Mountain Lion Usb From Dmg Windows 10
Drag and drop the 'InstallESD.dmg' into the 'Source' box in Disk Utility. Then click the 'Restore' button on the toolbar. Drag your newly formatted drive into the 'Destination' box, and click the 'Restore' button. The process should take about 30 minutes or so, less if your drive is particularly speedy.
UPDATE: Some users have reported getting a 'Could not restore – Invalid argument' error at the end of the restore process. Our testing shows the error message can be safely be ignored; the drive can be mounted and will boot your system to install Mountain Lion. As noted in the comments, however, mounting the InstallESD.dmg file before performing the restore process avoids triggering the error message.
If you are making a DVD, click 'Burn' and select the image as a source. Once Disk Utility is done, you will have a bootable install disk.
Create Bootable Mountain Lion Usb From Dmg Download
As with Lion, the install disk includes the same options as the emergency recovery partition created when you install Lion or Mountain Lion. With it, you'll be able to use Safari to find troubleshooting information, run Disk Utility to fix filesystem errors, restore from a Time Machine backup, or install Mountain Lion from scratch on any compatible Mac.