Type Y to confirm erasing the drive.
Fix a crashing or unbootable Mac when recovery mode fails.
At least 14.3 GB of available storage space to perform the upgrade.
Open your web browser and navigate to the official Apple Support page for legacy macOS downloads. macos high sierra 10136 dmg
Once your bootable media is ready, follow these steps to install the OS on your target Mac. Step 1: Boot from the USB Drive Shut down the Mac completely. Insert your bootable USB drive into a USB port.
A DMG file is an Apple disk image file that acts as a virtual installer disc. Having a standalone DMG file is highly beneficial for several reasons:
If your Mac supports macOS Mojave (10.14) or Catalina (10.15), upgrade. If your Mac is stuck on High Sierra due to hardware limits (pre-2012 models), consider migrating to (Ubuntu or Linux Mint) for security updates. Type Y to confirm erasing the drive
File sizes and contents
If you are downgrading or upgrading an older machine to this version, you will benefit from several structural changes made to the Apple ecosystem:
The internet is filled with third-party DMG download sites, but many contain malware, modified installers, or outdated beta versions. Open your web browser and navigate to the
hdiutil create -o /tmp/HighSierra -size 8000m -layout SPUD -fs HFS+J Use code with caution. Mount the new blank image:
Once you have the official installer app in your Applications folder, you can easily convert it into a standard DMG file yourself using the Terminal. This ensures your file is 100% genuine. Open (via Spotlight or Applications > Utilities). Paste the following command to create a blank disk image:
High Sierra introduces Apple File System (APFS), which optimizes solid-state drives (SSDs). If the conversion fails on a third-party SSD, it usually points to a compatibility issue with the drive's firmware.
Summary
macOS High Sierra 10.13.6 DMG: Direct Download & Installation Guide