How to make bootable USB drive of Mac OS X 10.10 Yosemite

By | June 7, 2014
Yosemite Main Windows

The new Mac OS X10.1o in not available for everyone as of now, but if you can arrange or have a copy of the Developer Preview or the public OS X Yosemite Beta (request your copy here), the next logical step is to create a bootable USB drive of it. Don’t worry I will help you throughout the process to make a bootable USB drive of OS X 10.10.

Yosemite Main Windows

Tough to say, this is not going to be as easy as it was when we created a bootable USB drive of earlier Mac OS, since this is a beta build, but it is very simple if you follow all the steps as it is mentioned below.

Before getting into the steps make sure that you have the installation app for Yosemite, If you want to install first, then make a bootable drive, make a copy of the install app in another location so you can access it later or even in another PC as well.

Warning: Don’t follow this tutorial with the torrented file of OS X 10.10. It’s recommended to use only the official downloaded OS X Yosemite Preview.

Follow the steps mentioned out there, if you get any kind of difficulties doing this comment below for the help,we are always there to help to get this awesome update on your PC.

How to make bootable USB drive of Mac OS X 10.10 Yosemite

Step 1: Format your USB drive

First, your USB drive’s size must be at least 8 GB, then mount it. Open up Disk Utility and do the following steps:

  • Select the USB drive and go to the Partition tab
  • Change the “Partition Layout” to 1 Partition
  • Rename it Yosemite, you can use any name 🙂
  • Select Mac OS Extended as the “Format
  • Click the Options button and select GUID Partition Table and hit OK.
    Yosemite 2
  • Confirm by click on Partition and wait for the format to complete. It will take few minutes.

Step 2: Open InstallESD

Your USB is ready, now you need to open the InstallESD.dmg.

  • Go to Applications and find the OS X 10.10 Yosemite Developer Preview app file.
  • Right click on it and select the option called “Show Package Contents“.
  • Go to the Contents->Shared Support and open InstallESD.dmg, wait for it to complete verifying.
  • As it mounts, you will see a new windows with Packages.
    Yosemite 3

Step 3: Unhide All files in Finder

There are few files in OS X which are hidden, you need to first make visible, to do so, open terminal and enter the command written below:

  • defaults write AppleShowAllFiles TRUE
  • killall Finder
    Yosemite 4

You will then see some of new file appeared you will see a file called “BaseSystem.dmg

Step 4: Restore your USB using BaseSystem.dmg

Now go back to the Disk utility and select the Yesomite partition of the mounted USB drive.

  • Open the Restore tab
  • Drag and drop Yosemite down to the Destination path
  • Drag and drop BaseSystem.dmg to the Source path
  • Hit the Restore button
    Yosemite 5

Then click on Erase button to begin the restore process, you need to give the admin password and hit OK, wait for few minutes and then you will see a new OX Base windows. Head over to the folder called System. Hit enter to inside this.Yosemite 6

Step 5: Transfer the Packages folder to your drive

Go open the System folder. A new window should pop up, and once it does, open the Installation folder. Then, go to your OS X Install ESD window and drag and drop the Packages folder inside of the Installation folder. Replace and hit enter to begin transfer.

Yosemite 7

Step 6: Copy the BaseSystem Files

Now go back to the root folder of your OS X base system partition and copy the BaseSystem.chunklist and BaseSystem.dmg files from the OS X Install ESD window where you got the Packages folder from.

Yosemite 8

Step 7: Hide All folder in Finder

Now you need hide the using Finder, open terminal and execute the command listed below

  • defaults write AppleShowAllFiles FALSE
  • killall Finder
    Yosemite 9

Step 8: Install OS X 10.10 Yosemite Preview on Mac

Restart your PC while holding the Option (Alt) key on your keyboard. Wait until the Startup Manager appears, then select your new OS X Base System volume(USB should be attached to your PC). Also, you can just hold down the C button while starting up to boot directly into the USB drive.

Yosemite 10


Comment below if you are having any issues regarding this, and also don’t forget to share after getting the latest OS X on your mac.