In Disk Utility, select your formatted USB drive partition, click the button at the top, select the mounted High Sierra image as the source, and click Restore . Installing macOS High Sierra: Step-by-Step

The DMG typically contains:

# 1. Create a blank disk image of 8GB hdiutil create -o /tmp/HighSierra -size 8000m -layout SPUD -fs HFS+J # 2. Mount the newly created image to your system hdiutil attach /tmp/HighSierra.dmg -noverify -mountpoint /Volumes/install_build # 3. Use Apple's built-in tool to write the installer files to the image sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/install_build --nointeraction # 4. Detach the newly created installer volume hdiutil detach /Volumes/Install\ macOS\ High\ Sierra # 5. Convert the temporary image into a final, high-quality read-only DMG file hdiutil convert /tmp/HighSierra.dmg -format UDZO -o ~/Desktop/macOS_High_Sierra_10.13.6.dmg # 6. Clean up the temporary file rm /tmp/HighSierra.dmg Use code with caution.

:If you already have 10.13.x and just need the 10.13.6 update, use the macOS High Sierra 10.13.6 Update DMG (1.88 GB).

If your Mac will not boot, or if you are configuring a Hackintosh or Virtual Machine from a Windows PC, you cannot access the Mac App Store. In this scenario, you must download a pre-compiled, high-quality DMG file from verified preservation archives like or dedicated tech repositories.

If you have a compatible Mac running an older or compatible OS, you can access the download link directly through Apple's support pages.

If you already downloaded such a DMG, . Verify its integrity by checking the InstallInfo.plist or comparing its SHA‑256 checksum against Apple’s (published in security forums).

If you are on a newer Mac and need the file for an older machine, you can use the native terminal tool to pull the package directly from Apple’s servers. Open ( /Applications/Utilities/Terminal.app ). Type the following command and press Enter:

Apple officially removed High Sierra from the Mac App Store for modern Macs, but the link still exists.

Dec 9, 2566 BE — download macOS High Sierra bootable dmg file from third-party and flash it to a USB drive to create a bootable install media. Reddit · r/MacOS How to download and install macOS - Apple Support

Mount your High Sierra DMG file by double-clicking it to reveal the "Install macOS High Sierra.app" inside. Drag this app into your folder.

Take the time to find a clean, uncorrupted image. Your legacy Mac (and your sanity) will thank you.

Released as the final refinement of the High Sierra generation, version 10.13.6 provides a highly stable environment for older Mac hardware.