I had to reinstall macOS to my mac mini, because I replaced HDD in my mac mini. I tried to reinstall macOS via the internet, but I could not, because of the limited bandwidth of my internet connection. Then I used the USB-installer.
The step of making USB-installer is described at the following WWW page.
How to create a bootable installer for macOS
The steps are the following:
- Download macOS from the App Store. When the macOS installer opens, quit it without continuing installation.
- Connect your Mac to the USB flash drive or other volume that will be
used as the bootable installer. Make sure that it has at least 12GB of
- Execute the following commands in Terminal(This example is for High Sierra).
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\ Sierra.app