This article provides a comprehensive guide on how to safely download, create a bootable installer, and install macOS Sierra using a DMG file. 1. Why Download macOS Sierra 10.12?
You must temporarily trick your Mac's internal clock into believing it is still the year 2016 or 2017 before launching the installer.
If a fresh installation is desired, open from the recovery screen, format your internal drive as Mac OS Extended (Journaled) , exit Disk Utility, and select Reinstall macOS . download macos sierra 1012 dmg file install
Once the "Install macOS Sierra" app is in your Applications folder, you can create a bootable USB drive for a clean installation. A USB flash drive with at least 16GB of space. The drive will be erased, so back up any existing data. The Process: Connect your USB drive to the Mac.
Click the link to download InstallOS.dmg as noted in Apple Support forums . The file will be saved to your folder. This article provides a comprehensive guide on how
Before downloading, ensure your hardware is compatible with version 10.12: Late 2009 or newer MacBook Air/Pro: 2010 or newer iMac: Late 2009 or newer Mac mini/Pro: 2010 or newer Memory: Minimum 2GB RAM (4GB recommended) Storage: At least 8.8GB of available space How to Download macOS Sierra 10.12 DMG
Find the executable application bundle named . You must temporarily trick your Mac's internal clock
Because Sierra is old, you may see an error saying the installer is "damaged" or "expired." This is due to expired Apple security certificates. Disconnect from the internet. Open Terminal from the Utilities menu in the installer. Type: date 010101012017 Press Enter. Try the installation again.
Once you have the "Install macOS Sierra.app" in your Applications folder, you can use that file to create a bootable USB installer drive. This allows you to perform a clean installation on a formatted drive, or install Sierra on multiple Macs without re-downloading. You'll need an .
Before downloading the installer, verify that your Mac is compatible with macOS Sierra. Compatible Mac Models Late 2009 or newer MacBook Air: Late 2010 or newer MacBook Pro: Mid 2010 or newer Mac mini: Late 2010 or newer iMac: Late 2009 or newer Mac Pro: Mid 2010 or newer Hardware Requirements Memory: Minimum 2 GB of RAM (4 GB recommended). Storage: At least 8.8 GB of available storage space. OS Version: OS X Lion 10.7.5 or later to upgrade directly. Step 1: Download the macOS Sierra 10.12 DMG File Safely
Navigate to the official Apple Support macOS Download Directory .