When you download the file from Apple, it arrives as InstallOS.dmg . Inside this disk image is an installer package named InstallOS.pkg . To turn this into a usable application file: Double-click the downloaded to mount it. Open the mounted volume and double-click InstallOS.pkg .
With your bootable USB ready, you can now perform a clean install or upgrade on any compatible Mac. Shut down the target Mac completely. Insert the bootable USB drive into an available USB port. Download Mac Os Sierra 10.12 Dmg
Type your Mac’s administrator password when prompted (no characters will show on screen for security) and press . When you download the file from Apple, it
If you can tell me the and year of your Mac, I can confirm if it is supported and give you a more customized guide. Open the mounted volume and double-click InstallOS
If your Mac originally shipped with Sierra: