To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.
Learn how to upgrade to macOS Big Sur, the latest version of macOS.
Copy the ‘Install OS X Mountain Lion.app' folder from your 10.8.4 installer disc to the Applications folder Create a 8 GB or larger partition on the target drive to host the patched installer. The volume label should be Install and it should be automatically mounted at /Volumes/Install. Select the orange 'Mac OS X' option and you will boot into the OS X Mountain Lion installer, from here installation is the same as normal. Click on Continue, select the destination drive, and install.
Check compatibility
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation.
To confirm compatibility before downloading, check the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also find compatibility information on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.
Make a backup
Before installing, it's a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.
Mountain Lion Os Iso
Download macOS
It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection. Lightroom classic download for mac.
Safari uses these links to find the old installers in the App Store. Convert pdf to pages file on mac. After downloading from the App Store, the installer opens automatically.
- macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
- macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
- macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Mac lion versions. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.
- macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
- OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
- OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard
Install macOS
Follow the onscreen instructions in the installer. It might be easiest to begin installation in the evening so that it can complete overnight, if needed.
If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.
Install Mountain Lion On Unsupported Mac
Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs macOS and related firmware updates.
Install Mountain Lion Macbook
Learn more
You might also be able to use macOS Recovery to reinstall the macOS you're using now, upgrade to the latest compatible macOS, or install the macOS that came with your Mac.
