I'm trying to install Mavericks from a bootable USB. I'm using this guide; http://macpaw.com/how-to/clean-install-os-x-mavericks-on-my-mac

I delete El Capitan in disk utility, but there is no 'Install OS X', merely 'Reinstall OS X', which asks me to reinstall El Capitan.

Where is the option to roll back to previous operating systems?

EDIT: This is on an early 2015 model Apple Air.

  • Did you download Mavericks from the App Store?
    – Allan
    Commented Apr 24, 2016 at 20:50
  • General rule is, you cannot install any OS older than the machine itself. That machine came with Yosemite, so won't accept Mavericks.
    – Tetsujin
    Commented Apr 25, 2016 at 6:49

1 Answer 1


You have not written what your MAC, ie, it is unclear whether the installation it is possible Mavericks.

Minimum Supported Operating System for your computer can be viewed using Mactracker or MachineProfile


Back in February, Apple's Worldwide Developer Certificate, designed to verify third-party apps and services, expired, requiring Apple to issue a new certificate for developers to use. OS X installation files downloaded from the Mac App Store before February 14, 2016 and stored on a computer or USB drive are no longer functional. This includes installation files for OS X El Capitan and older versions of OS X like Mavericks and Mountain Lion. Users who keep OS X installers on hand or have created USB install disks in case of emergencies should replace their files with new versions by re-downloading them through the Mac App Store using purchased history.

Users who can't replace an expired certificate can still use older installers by changing the dates on their machines.

  1. In the OS X Installer, choose Utilities > Terminal.

  2. Enter date 0201010116 and press Return.

  3. Quit Terminal and continue the install.

OS X Installers Downloaded Prior to February 14 No Longer Work After Certificate Update

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