The machine will begin writing system components to disk before restarting automatically to complete the full installation phase.
Before downloading the file, verify that your Mac supports macOS Sierra. Running this operating system on unsupported hardware can cause system instability. macOS Sierra officially supports the following 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
Once the USB is ready:
This report provides the necessary steps to download and install macOS Sierra (version 10.12) using a disk image (.dmg) file. While macOS Sierra is no longer receiving security updates , it remains available for users with older, compatible hardware.
Disconnect your Mac from the internet. Open Terminal before starting the installation and change the system clock to a date closer to Sierra's release lifecycle. Type date 0101100017 (January 1st, 2017) and press Enter . Close Terminal and restart the installer. Error: "An error occurred while preparing the installation" download macos sierra 1012 dmg file install
Once you have the installer, the journey isn't over. While you can use the standard Terminal command to create a bootable USB, you should be prepared with DiskMaker X as a more reliable fallback solution.
Once you've found a reliable source, click on the download link to obtain the macOS Sierra 10.12 DMG file. The file size is approximately 5.2 GB. The machine will begin writing system components to
Open the mounted image and double-click the InstallOS.pkg file.