El Capitan Could Not Be Installed On Your Computer

I updated two computers from Yosemite to El Capitan with no problem. Then I tried to update a friend's computer from 10.6.8 Snow Leopard to El Capitan and I got caught up in the limbo where it keeps downloading but won't install and worse yet, won't go back to the previous system. Answer (1 of 2): You will need to be more specific. The 'cannot be used from this drive' message usually means you placed the installer file itself on a disk that is.

El Capitan Could Not Be Installed On Your Computer Using

Install

El Capitan Could Not Be Installed On Your Computer To Find

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. This happens because the the installer certificates are no longer valid when checked against the clock of your mac.

Don’t panic though as this is easily fixed using Terminal, so don’t restart immediately.

El Capitan Could Not Be Installed On Your Computer

  • Click Utilities on the menu bar
  • Select Terminal
  • Type date 062112422016
  • Exit Terminal
  • Click Restart

Mac Os El Capitan Install

When you restart the mac and try the installer again it will now believe the certificates are valid and will continue as it should.