is only the first step. You must "extract" the actual application to your Applications
Double-click the downloaded file to mount it. download macos sierra 1012 dmg file install
If your Mac is already running a compatible OS, you can try the macOS Sierra App Store link . 2. Prepare the Installer Once the InstallOS.dmg file has finished downloading: Mount the DMG: Double-click the .dmg file to open it. is only the first step
Open Safari and navigate to the official Apple Support page for old macOS versions. Scroll down to the "macOS Sierra 10.12" section. download macos sierra 1012 dmg file install
Visit the official Apple Support page for older macOS versions. Locate the download link.