Introduction

Apple officially released OS X 10.11 El Capitan operating system in September 2015 as an update through Apple App Store. This actualization will update core of your system and preserve your user data.

Having no luck making the USB installer, because the El Capitan pkg installer won't run on big sur to create the installer app. I tried to use the internet installer that came with it, but it would not work without signing into the original owner's AppleID (even though I specifically went into iTunes to 'De-Authorize this computer' before wiping the original installation) Instead, I downloaded the 'El Capitan' installer.dmg file from Apple's support page: https.

However, if you want to have a clean installation of El Capitan on your Mac you will need to create a special installation USB drive and in this article we will show you how.

Four ways how to create El Capitan USB installation flash drive:

Preparation - get OS X El Capitan installer and USB flash drive

Download El Capitan installer (Install OS X El Capitan.app in Applications folder) available in Mac App Store.

Prepare a flash drive with OS X Disk Utility. Format it with GUID Partition Table and name it as Untitled. The minimal capacity of flash drive must be 8 GB.

How to create El Capitan installation USB drive with createinstallmedia tool

Install El Capitan Dmg

The createinstallmedia is a command line tool distributed with OS X installer.

When you have prepared your USB flash drive and El Capitan installer is downloaded from App Store ► open Terminal and type command:

sudo /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install OS X El Capitan.app --nointeraction

In our case 'Untitled' is the name of USB flash drive! Replace 'Untilled' by name of your flash drive.
Wait a few minutes and your El Capitan installation USB drive will be prepared.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation with Terminal commands

When your USB flash drive is ready and El Capitan installer downloaded from App Store ► Open Terminal and type the following sequence of commands:

sudo hdiutil attach /Applications/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg

sudo asr restore -source /Volumes/OS X Install ESD/BaseSystem.dmg -target /Volumes/Untitled -erase -format HFS+

sudo rm /Volumes/OS X Base System/System/Installation/Packages

sudo cp -a /Volumes/OS X Install ESD/Packages /Volumes/OS X Base System/System/Installation/Packages

sudo cp -a /Volumes/OS X Install ESD/BaseSystem.chunklist /Volumes/OS X Base System

sudo cp -a /Volumes/OS X Install ESD/BaseSystem.chunklist /Volumes/OS X Base System

sudo cp -a /Volumes/OS X Install ESD/BaseSystem.dmg /Volumes/OS X Base System

hdiutil detach /Volumes/OS X Install ESD

Now wait until your bootable installation flash drive with OS X 10.11 El Capitan is made.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation with Disk Utility and Finder

When your USB flash drive is ready and El Capitan installer downloaded from App Store ► Open Terminal and type:

defaults write com.apple.finder AppleShowAllFiles 1 && killall Finder

This command allows you to view hidden files in Finder.

Now Open Finder ► Applications ► Install OS X El Capitan.app ► right click ► Select Show Package Contents option.

Navigate to Contents/SharedSupport ► Mount InstallESD.dmg file

Create El Capitan Usb Installer

Open OS X Install ESD archive in Finder and mount BaseSystem.dmg archive

Connect USB drive and open Disk Utility (/Applications/Utilities)

Select the USB drive from the list of disks, select Restore tab and pick Select OS X Base System archive as a source and USB flash drive as the destination. When ready click on Restore button.

After the Restore process is finished, open Finder ► open USB drive (OS X Base System) ► go to the System/Installation folder and select Packages file and delete it.

Open OS X Install ESD volume in Finder, select Packages folder and copy them to System/Installation folder on USB drive.

Also copy BaseSystem.chunklist and BaseSystem.dmg files from InstallESD.dmg volume to root of USB flash drive (OS X Base System).

Now your El Capitan installation USB drive is prepared and ready for use.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation disk with DiskMaker X

DiskMaker X tool is Wizard like tool that allows you create OS X installation disk. Download DiskMaker X to your Mac and copy it to Applications folder.

When you have prepared your USB flash drive and El Capitan installer is downloaded from App Store ► open DiskMaker X.

Select version of OS X (in our case El Capitan)

Select copy of OS X installation app

Create Bootable El Capitan Installer

Select USB drive that will be used for USB installation

And wait a few minutes till the the DiskMaker X finish creating process.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.