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Unlike an upgrade, installing Sierra from scratch can iron out issues like quirky drivers, sluggish performance, and unnecessary hard drive bloat.

Because a clean install will erase your hard drive, youll want to back up your data before you begin.

Sierra Cleaner 3.1.2 Download The MacOS

Learn how to download the macOS Sierra installer, create a bootable installation disk, and make your Mac feel brand new again.

You should see something like MacBook Pro (13-inch, Early 2015) just beneath the operating version number.

The drive can be any sort of hard drive (including a flash drive), and should have a minimum of 16GB of disk space.

Use the backup method of your choice to preserve your personal files, such as photos and documents.

Youll see a hard drive icon appear on the desktop when the drive mounts.

Use your mouse to highlight the following (lengthy) command, then press Cmd C to copy.

When the password is accepted, youll see a message asking you to confirm that you want to erase the disk.

The bootable version of the Sierra installer will start copying to your USB drive.

Dont walk away from the computer, though Youll need to take action as soon as it turns back on.

After a few seconds youll see a list of bootable drives connected to your Mac.

The left side contains a list of drives connected to the computer.

When you click the drive, its properties will appear in the center pane.

After clicking, youll see a pop-up asking you to set some parameters.

The utility will now format your hard drive, which may take several minutes.

Youll see a confirmation message once the drive has finished formatting.

Now youll be prompted to select a drive on which youll install Sierra.

For most people, its the only drive in the computer (and in most cases, its called Macintosh HD).

When the process is complete, your computer will boot to your brand new macOS Sierra desktop.

Back up your Mac.

Sierra Cleaner 3.1.2 Download The Installer

Go to. 3. Download the installer.

Create a bootable USB install drive.

Boot from the drive.

Open Disk Utility.

Format your startup drive.