So before you download and install macOS For information on how to do this, head over to our ultimate guide to backing up your Mac. The final release of macOS Leading into this, some Apple fanatics opted to install macOS Since the release some people have encountered some problems, so we'd recommend checking out our guide on macOS Apple has also released macOS High Sierra We'd highly recommend you download and install macOS High Sierra Whenever you make the move to a fresh-off-the-shelf new operating system, we highly recommend backing up the files on your Mac, so if anything goes wrong you can quickly restore your machine to its previous working order. This latest version of the operating system that runs on Macs and MacBooks comes with a number of great new features.