Install Disk Creator
Install Disk Creator simplifies creating a bootable OS X installer.
When you install a new major version of OS X, or after some time has passed, it is a good idea to do a clean install (that is, to erase the disk you are installing OS X onto as part of the installation process).
That will make your Mac run blazingly fast for a few months or more, and many people report that it fixes longstanding problems they’ve had too.
Here is my clean install procedure which I perform at least every time a new version of macOS is released:
- Download the macOS update from the App Store.
- Backup all the data to an external disk with a clone. Two options are to use Duplicate (a free utility which can copy and paste an entire bootable volume), or Mac Backup Guru (a paid, fully featured backup utility with unique incremental backups capability) for that.
- Create a bootable USB Installer with Install Disk Creator and install it onto the startup disk. Boot up from the fresh macOS installation.
- Go to the backup disk and use e.g. Duplicate or Mac Backup Guru to select Copy on the home folder (eg: /Volumes/External Backup/Users/Bob) and then Paste on the new /Users folder on the clean install disk. This migrates all of the data and settings. Then migrate the applications by selecting Copy on the Applications folder on the backup disk then Paste on the new /Applications folder. All of the files each application needs, and its settings, will have already been migrated by copying and pasting the home folder.