How to make a bootable Sierra installer drive in case you want to downgrade from macOS High Sierra

macOS High Sierra is a working beta, but what if you want to keep a copy of macOS Sierra, too?If you are preparing to test out macOS High Sierra, there is one additional set of steps you should follow. You should download a bootable copy of macOS Sierra. This allows you to use it if you partition your hard drive for dual-software installation.

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How to make a bootable Sierra installer drive in case you want to downgrade from macOS High Sierra