Once you have the official installer, the best way to use it is to create a bootable USB. This is much more reliable than trying to run a random DMG file.
Use the createinstallmedia command in Terminal to burn the installer to your drive: sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume 4. Using Google Drive on High Sierra macos high sierra 10136 dmg google drive best
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSBName Once you have the official installer, the best