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.
Find out how to upgrade to macOS Big Sur, the latest version of macOS.
Check compatibility
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it may state that your Mac doesn't have enough free storage space for the installation or that the installer is too old to be opened on this version of macOS.
If you want to check compatibility before downloading the installer, find out more about the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan or Yosemite. You can also check compatible operating systems 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. Find out how to back up your Mac.
Install Mountain Lion Mac
On July 25, 2012 Apple released Mountain Lion (OS X 10.8) as an upgrade to its operating system. Mountain Lion reportedly has over 200 new features, and is available through the Mac App Store for $19.99. If you bought a new Mac on or after June 11, Apple will give you an upgrade for free.
Read the tutorial on how to re-download the OS X Mountain Lion installer from the Mac App Store. After many inquiries from our users, here is a guide on how to re-download the OS X Mountain Lion installer from the Mac App Store. If not, you'll need to re-download it from the Mac App Store. Launch the App Store and ⌥-click the Purchases tab. An 'Install' button should appear next to Lion. Click it to re-download the installer. Once the installer finishes downloading, go to your Applications folder to find the installer itself. It is called Install Mac OS X Lion. The Mac App Store does allow to resume a download, however things do not seem to work out always as expected - to be safe download it all in one piece. Yesterday, I downloaded Mountain Lion from the Mac App Store - halted it - and resumed later without having restarted the Mac. The whole download started over.
Download macOS
It takes time to download and install macOS, so make sure you're plugged into AC power and have a reliable Internet connection.
Download Mountain Lion From Mac App Store Near Me
These installers from the App Store will open automatically after you've downloaded them:
- macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite or Mavericks
- macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks or Mountain Lion
- macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion or Lion
Your web browser will download the following older installers as a disk image called InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It will install an app named Install [Version Name]. Open that app from your Applications folder to start 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 may be easiest to start the installation in the evening so that it can be completed 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.
Download Mountain Lion From Mac App Store
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 both macOS and related updates to your Mac firmware.
Mac Apple Store Download Apps
Learn more
Download Mountain Lion From Mac App Store To My
You may 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.