I created a USB disk with a bootable El Capitan as per this documentation. Plug-in your USB key on a turned-off computer. Start your Mac, press immediately OPTION (aka ALT) Select the Orange icon (aka a USB stick) labelled El Capitan. If it does not detect it after 10 sec and you only see your hard-drive. Try another USB port and wait 10 sec again. Jun 11, 2021 If upgrading from macOS Sierra or later, your Mac needs 35.5GB of available storage to upgrade. If upgrading from an earlier release, your Mac needs up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur. OS X could not be installed on your computer. No packages were eligible for install. Contact the software manufacturer for assistance. Quit the installer to restart your computer and try again. Oh dear When trying to install OS X 10.11 (El Capitan) you may encounter this message.

El Capitan Cannot Be Installed On This Computer

To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.

Install

Learn how to upgrade to macOS Big Sur, the latest version of macOS.

Could

Check compatibility

Can't Install El Capitan

The version of macOS that came with your Mac is the earliest version it can use. For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier.

If a macOS can't be used on your Mac, the App Store or installer will let you know. For example, it might say that it's not compatible with this device or is too old to be opened on this version of macOS. To confirm compatibility before downloading, check the minimum hardware requirements:

  • macOS Catalina 10.15 hardware requirements
  • macOS Mojave 10.14 hardware requirements
  • macOS High Sierra 10.13 hardware requirements
  • macOS Sierra 10.12 hardware requirements
  • OS X El Capitan 10.11 hardware requirements
  • OS X Yosemite 10.10 hardware requirements

Download macOS using Safari on your Mac

This

Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.

  • macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
  • macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
  • macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion

El Capitan Cannot Be Installed On This Computer

Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.

El Capitan Cannot Be Installed On This Computer As A

  • macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
  • OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
  • OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard