Installing Mac OS X from USB flash drive

Last modified
Wednesday, July 17, 2019

This guide has been written by myself so hope you like it.

Installing Mac OS X from a USB flash drive

This guide will show you how to create a bootable USB flash drive to install Mac OS X. Here are the prerequisites.
A USB flash drive that's at least 8 GB in size. The installer and other files take up at least this space.
A program called DiskMakerX previously known as Lion Disk Maker available from
The latest version of a supported operating system (Lion, Mountain Lion or Mavericks) available from the Mac App Store.

1. Download the above two apps listed in the prerequisites.
After downloading the latest supported operating system from the Mac App Store the installer opens automatically. Do not proceed since the file will be erased upon the reboot. Instead, press command-q at the first screen of the installer where the continue button has the keyboard focus.
2. Open the DiskMakerX disk image in the finder. It should then appear in the image browser. You can accomplish this by highlighting the dmg file with just arrow keys and press command-o for open.
3. For reasons of better accessibility I then switch to list view with command-2. Copy the only .app file in there and paste into your applications folder. This is accomplished with command-c for copy, command-shift-a to open the Applications folder and command-v to paste. Once copied close all Finder windows with command-w so you're at the desktop and eject the disk image by first highlighting it with just arrow keys and press command-e for eject.
5. Connect the USB flash drive to your mac before beginning the next step.
6. Open the DiskMakerX which should now be located in your applications folder.
7. When prompted that Safari has downloaded this application from the web vo-arrow to the open button and press vo-space to activate. With QuickNav enabled with left-right arrows together you can simply navigate to the open button with left or right arrow keys then press up-down arrows together to activate.
By VO throughout this guide I am talking about the VoiceOver keys which are control-option.
8. Follow the instructions on the screen. For example when choosing the operating system click either Lion, Mountain Lion or Mavericks button.
9. When it comes to the USB flash drive part choose to have it create as an 8 GB flash drive. You will be warned that all data will be erased so make sure your flash drive is backed up somewhere.
If you have previously made a bootable USB flash drive you can update the volume here by clicking the appropriate button.
Since the application uses appropriate options as default buttons in most cases, pressing return will be enough to move on to the next screen.
10. The preparation and copying will eventually begin. Do not worry about any busy busy busy messages or that the app has no windows. It is just doing its work behind the scenes. Please enter any credentials when prompted. VoiceOver makes a clicking type sound when in password text fields.
11. When all finished, you are invited to either open Start-up Disk preferences so you can quickly change to the newly created or updated bootable USB flash drive and test your creations. You are also invited to make a donation to the developers which is in fact the default button so pressing return will open your browser allowing you to make such a donation. Finally there is a quit button which does what it says; quit the application. Let's then click the open Start-up Disk Preferences button.
12. Interact with the possible start-up disks scroll area, choose your bootable USB Flash Drive by selecting the appropriate radio buttons, stop interacting with the scroll area and click restart button. To interact and stop interact with VoiceOver do one of the following:
A. Press vo-shift-down arrow to interact; vo-shift-up arrow to stop interacting.
B. Press down-right arrows to interact; down-left arrows to stop interacting. This is assuming QuickNav is enabled with left-right arrows.
13. Click restart button again to confirm you want to restart the computer.
14. Your USB flash drive should now boot up and eventually display the Mac OS X Utilities with the applications table having keyboard focus. How long it takes depends on your USB flash drive. On my Verbatim 64 GB USB flash drive it takes about thirty seconds.
15. To enable the whole operation to talk and output to Braille if you have such facilities requires starting VoiceOver. To do this press command-F5. You may hear a different voice than what you're used to. This is because in effect a temporary copy of VoiceOver used for installation and other purposes is running and so the voice is set to Fred which runs on even older hardware. If using Braille only USB refreshable Braille displays will be supported at this time.
16. To manage your disks including partitioning, select Disk Utility and click continue button.
Should you wish to repartition your disk, please be aware all data previously stored on the disk will be erased. Make sure you have a disk backup somewhere.
17. Let's for example structure the disk so you have one big partition. To do this:
a. Interact with the disks table and choose the topmost column which is your entire disk and not just your start-up partition.
b. Stop interacting with the disks table, click the partition tab to select it, choose 1 from the partition layout pop-up button and click apply button. Interacting with a pop-up button involves activating the item with either vo-space (up-down arrows if QuickNav is enabled), space or return.
The current option allows you to manage the partitions on the disk without losing data.
18. Confirm you wish to layout the partition this way by clicking the partition button. It will then go away and do its thing. This should take a matter of seconds. You will even see it format the disk with the appropriate file system and disk label which you can also choose before applying the new layout.
19. When all finished quit Disk Utility with command-q and return to the OS X Utilities screen.
20. Now it's time to install Mac OS X from the bootable USB flash drive. So interact with the applications table, choose Install Mac OS X, stop interacting with the applications table and click continue button.
21. It is now a matter of just following the on screen instructions.
At the final step of the installer before it does its work, VoiceOver appears to lose focus. You will know this as attempting to navigate will only result in a ding. To get around this press VO-F2-F2 to open the Window Chooser menu, down arrow to the Installer and press return. You should now be able to select the disk you wish to install OS X on and click the install button.
At the preparing to install screen, when it says about a second remaining and it's at 99.9% the installer appears to hang. Do not panic and certainly do not do a thing. Just walk away, grab your favourite refreshments and before you know it the mac will suddenly boot to the installer now stored on the hard disk.
I hope you find this guide to be of use. Any comments good or bad will be very welcome. Thank you and happy reading!


The article on this page has generously been submitted by a member of the AppleVis community. As AppleVis is a community-powered website, we make no guarantee, either express or implied, of the accuracy or completeness of the information.



Submitted by walkseasy on Monday, June 23, 2014

What is the advantage of using the disk maker program over using the standard bootable disk maker app provided on The Apple Support web site?

Submitted by splyt on Monday, June 23, 2014

I do not have a 8 gig pen drive but have instead a huge usb hard disk. Can I create a 8 7 partition and use it instead? How to instruct the maker abnd the whole OS to use this partition?


Submitted by KE7ZUM on Monday, June 23, 2014

For those that want to use the deag drop method I've written a guide here talkign about how to do just that usign the drag drop method. I mainly wrote it for myself but here you go.

Submitted by Guillaume Gète on Saturday, June 28, 2014


I am DiskMaker X's developer. Thanks for this guide ! I'll try to make a small blog post about it :-)
@Walkeasy : DiskMaker X makes a full install disk, while Apple's tool only builds a boot disk which will request to download the full installler for every user. DiskMaker X is more interesting if you have many Macs.

@splyt : SD cards are fully supported :-)