Once you have the in your Applications folder, follow these Terminal steps to create the ISO :
mv /tmp/HighSierra.cdr ~/Desktop/HighSierra.iso 3. System Requirements & Compatibility
hdiutil create -o /tmp/HighSierra -size 5600m -layout SPUD -fs HFS+J mac os high sierra download iso
Since you likely need the ISO file itself, here is the standard method to create it from the official Apple installer. This ensures you have a clean, unmodified system image.
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/install_build Once you have the in your Applications folder,
Avoid downloading pre-made ISOs from third-party "warez" sites. These can contain malware. If you must use a third-party source, the Internet Archive is a common community-driven alternative, though official sources are always safer . 2. Creating the ISO from the Installer App
Note: Ensure the installer is in your Applications folder. sudo /Applications/Install\ macOS\ High\ Sierra
Here is a useful review and guide regarding the , covering its current relevance, where to get it safely, and the preparation process.