I'm trying to install El Capitan on the boot drive of a 27' late 2014 iMac from an external drive. I am currently booted from a USB external drive that is running 10.13.16. I have downloaded a copy of the El Capitan installer. Quit Disk Utility and install El Capitan. If you already attached the SSD you can use Internet Recovery Mode (hold cmdR or altcmdR while booting) to first partition the new internal drive and then restore the original system (10.7 Lion). Then - after configuring Lion - you can to upgrade to El Capitan.
Trying to install El Capitan on using the USB drive method on my mid 2012 13' macbook pro (9,2) and I can't seem to get it to work at all. Using a PNY CS1311 240GB SSD. When it begins installing El Capitan I get about a minute before it stops and says 'OS X could not be installed on your computer. Couldn't complete copy'. I've tried a few times without any luck, and upon booting my laptop for the first time with the SSD I erased, then formatted with OS X Extended (Journaled) and GUID partition map, so I know it's formatted correctly.
I've successfully installed OSX on my old HDD using the same USB drive so I'm not really sure if that's the issue.
El Capitan Boot Disk
Any advice is greatly appreciated.
Create El Capitan Usb Installer
Posted on Apr 23, 2016 3:50 PM