This method requires you to make a bootable copy of the macOS Sierra installer, which you can use to boot from and then erase your Macs current startup drive.

Tom Nelson is an engineer, programmer, network manager, and computer network and systems designer who has written for Other World Computing,and others.

Sierra Upgrade Install Methods

The same install and upgrade install methods familiar to most Mac users are supported by macOS Sierra.

If you would rather perform an upgrade installation, visit our complete guide to upgrading to macOS Sierra.

The upgrade install is the easiest way to upgrade your Mac to macOS Sierra.

This method preserves all of your current user data, documents, and apps while upgrading the existing operating system on your Macs startup drive to macOS Sierra.

The advantage is that once the upgrade is complete, your Mac is ready to go, with all of your personal data intact and ready to use.

The clean install option, on the other hand, replaces the contents of the target drive, wiping away any existing data on the drive and replacing it with a pristine copy of macOS Sierra.

Sierra Software Problems With

A clean install is a good choice if you are experiencing software problems with your Mac and unable to resolve them.

While a clean install may solve the issue, you are starting from scratch; all of your current user data and applications will be gone.

Once youve determined that your Mac is capable of running macOS Sierra, you will need the following.

A 16 GB USB flash drive - The flash drive is needed for a clean install on your Macs startup drive.

If you plan to use the clean install on a non-startup drive, you dont need the USB flash drive.

A current backup of your Mac - We highly recommend making a clone of your Mac before performing the update.

This will allow you to easily return your Mac to the condition it was in before you installed macOS Sierra.

At the very least, you should have a current Time Machine backup or the equivalent.

There are two types of clean installs that can be performed with the macOS Sierra installer on your Mac.

Each has slightly different requirements, but the end result is a pristine version of macOS Sierra installed on your Mac.

The first type is to install the OS on an empty volume or drive, or on a target drive whose data you dont mind losing.

You dont need to make a bootable copy of the installer since you can run the installer directly from your Macs startup drive.

For this method to work, you need to have an available second drive or volume.

For most Macs, that means an external drive of some type, which will become the target for the installation and will also become the startup drive whenever you choose to boot into macOS Sierra.

How To Download Mac Os Sierra