Click on “Options” and select “GUID Partition Table”, and click “OK”, followed by “Apply”, then quit out of Disk Utility.Now go to the “Partition” tab and change the partition layout to “1 Partition”, then change the name of the partition to “ElCapInstaller” or another name of your choosing.Format the USB flash drive as “Mac OS Extended (Journaled)” and choose Erase to confirm the process – this formats the USB drive which will become the installer, be absolutely certain you have selected the right volume or you will lose data.Connect the USB drive to the Mac and launch Disk Utility, then select the USB drive from the left side menu and go to the “Erase” tab.Make an OS X El Capitan GM / Beta Bootable Installer Drive

Beyond that, we’re going to assume you have an appropriately sized USB drive ready, and the “Install OS X 10.11” application file residing in the /Applications/ folder of OS X, which is where it downloads to by default. Naturally, you’ll also need a OS X 10.11 compatible Mac for the destination. The OS X El Capitan installer application, this can be downloaded from Apple (either as Public Beta or Developer Beta, or preferably the GM Candidate).

An 8GB or larger USB Flash Drive, this will be formatted and turn into the OS X El Capitan bootable installer.

The basic requirements to make a bootable OS X El Capitan install drive are as follows:

Bootable el capitan