If you need to perform a clean install, you must create a bootable USB drive (minimum 8GB) using the createinstallmedia command in Terminal. Microsoft Community Hub Find out which macOS your Mac is using - Apple Support
2GB RAM minimum (4GB recommended) and 8.8GB of available storage. Existing OS:
Must be running OS X 10.6.8 (Snow Leopard) or later to upgrade directly. 2. Official Download Link
Obtaining the Mac OS X El Capitan 10.11.6 installer is essential for maintaining older hardware that cannot run newer macOS versions. Use this guide to safely download the official disk image ( ) and prepare it for installation. 1. System Compatibility Check