Only obtain the DMG (or the .app installer) from a source that provides the Apple-issued certificate or direct Apple CDN (Content Delivery Network) links.
With your bootable USB drive ready, you can perform a clean installation: download macos high sierra 10.13 6 dmg file
macOS High Sierra 10.13.6 full installer - Apple Communities Only obtain the DMG (or the
Because High Sierra is no longer the latest OS, Apple hides the direct download link from the main App Store page. However, you can still obtain it legitimately through the following methods. macOS High Sierra (version 10
macOS High Sierra (version 10.13.6) remains a crucial operating system for users running older Mac hardware, setting up virtual machines, or reviving legacy software. This comprehensive guide provides verified, secure methods to download the official macOS High Sierra 10.13.6 DMG file directly from Apple, along with step-by-step instructions to create a bootable USB installer. Why You Need a macOS High Sierra DMG File
http://updates-http.cdn-apple.com/2019/cert/061-39476-20191023-48f365f4-0015-4c41-9f44-39d3d2aca067/InstallOS.dmg Note: This URL is a direct link to Apple's servers. Because it is a legacy file, the installer inside may require a date modification trick (explained in the troubleshooting section below) to run on modern hardware.