Installing macOS High Sierra 10.13.6 from a DMG is feasible and sometimes necessary for legacy systems, provided the user carefully verifies the image’s integrity, prepares bootable media correctly, and accounts for certificate expiry. The process is more technical than the standard installer but offers greater control for offline or air-gapped environments. Future work should explore automated validation tools for legacy macOS DMG images.
Remember: always verify checksums (SHA-1) of your DMG against Apple’s official hashes if possible, and keep a backup of your installer on an external drive or NAS. High Sierra 10.13.6 may be “old,” but for the machines that run it, it is timeless.
Exit Disk Utility and select "Install macOS" to follow the on-screen prompts. 4. Compatibility and Support Supported Models:
macOS High Sierra - Technical Specifications - Apple Support
Press , type your admin password, and wait for the process to finish. Step 3: Installing macOS High Sierra 10.13.6
If you are installing over an old HFS+ formatted drive, the installer attempts to convert the file system to APFS.