Launch Terminal.app to enter a command to unhide the file and folder on your MAC. First, we need to unhide the files located in this newly mounted OS X Install ESD image. Don’t do anything with this Packages folder just yet. Once the verify process is done you will see the Package Folder. This will start the verify process on your MAC. Now navigate to Contents -> SharedSupport and open InstallESD.dmg Right-click the installer and select Show Package Contents from the context menu. Go to Applications again and find the Install OS X 10.10 Developer Preview app that you downloaded.

Now the USB part is over and lets move to the OS X Yosemite installer package. Now the partition process will start and this will take some time to format and making USB drive as a 1 partition After that hit the “Ok” button then “Partition” button. And enter the Partition information Name: ”yosemite”, Format: “Mac OS Extended (Journaled)”. Under Partition Layout, select 1 Partition from the drop-down menu. Now in the app select the USB drive and Selct the Partition Tab. Insert the USB drive or Disc on youir MAC and run the Disk Utility app from the Applications > Utilities folder. To get started all you nee a *GB or above USB drive, Apple computer with Mac App Store (10.6.8+) and OS X Yosemite installer. Once you have the installation app for Yosemite (Install OS X 10.10 Developer Preview), don’t install it directly, other wise you will lose the file and can’t make the USB disc. If you are interested in new OS and want to try it then sign up for the OS X Beta Program here, which will allow them to test the new OS, if selected. We all know that Yosemite OS X is the latest operating system form Apple, which comes with lots of new features and improvement. Here is the complete step by step guide which you can follow on your MAC create the bootable USB disc. Want to learn how to create a bootable USB installer for OS X Yosemite?.

Download yosemite dmg bootable