This will copy all of the applications which are present on the backup disk but not present on the startup disk to your new Applications folder, and automatically skip any applications which are already on the startup disk. Then migrate the applications by selecting Copy on the External Backup/Applications folder on the backup disk then Paste on the startup disk (eg: Macintosh HD). When ready, click Create macOS installer. Just click on the name of your USB drive that you wish to make bootable. Then in the next column, choose the destination.

This migrates all of your personal data and settings to your new home folder. Under Choose macOS installer, you’ll find all of the available operating system files. Go to the backup disk and use Duplicate (free) or Mac Backup Guru to right-click and select Copy on the home folder (eg: External Backup/Users/Bob) and then Paste on the Macintosh HD/Users folder on the startup disk. Note: The Finder’s built-in “Copy” and “Paste” will not work for the following.Boot up from this newly created startup disk. Erase the startup disk and install macOS onto it. Create a bootable USB Installer with Install Disk Creator and boot from it.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. Backup all the data to an external disk with a clone.You can download macOS High Sierra by clicking here. Download the macOS installer from the App Store.Here is the clean install procedure which can be performed at least every time a new version of macOS is released: Create Os X Installer Usb

Universal usb installer mac