: You need a USB flash drive with at least 16GB of capacity. Use Disk Utility to format it as Mac OS Extended (Journaled) with a GUID Partition Map . Create the Installer :
: Use the createinstallmedia command in Terminal. For High Sierra, the command typically looks like this (assuming your drive is named "MyVolume"): sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume . macos_high_sierra_10.13
: If you only have access to a PC, you can use TransMac to restore a High Sierra DMG file to a USB drive. Key System Requirements & Features : You need a USB flash drive with at least 16GB of capacity
: Use apps like DiskMaker X , which automate the process through a simple interface. macos_high_sierra_10.13