Install & Upgrade to OS X Mountain Lion on Multiple Macs with a Single Purchase
Multi-Mac households can buy OS X Mountain Lion once for $19.99 and use that single purchase to install and upgrade all of their other personal authorized Macs.
This is allowed by Apple’s generous Mac App Store licensing agreement that began with Lion, and though most people don’t bother to read the fine print, here’s the section of the OS X Mountain Lion 10.8 License Agreement that pertains to the matter:
“(i) to download, install, use, and run for personal, non-commercial use, one (1) copy of the Apple Software directly on each Apple-branded computer running OS X Lion or OS X Snow Leopard (“Mac computer”) that you own or control.”
Basically that means as long as the Macs share the same Apple ID, you will be able to easily re-download Mountain Lion on another Mac, whether it’s running Lion or Snow Leopard. You can also just copy the Installer over, or manually make a bootable Mountain Lion installer drive and use that to upgrade the other Macs in the household. Here are several approaches to getting the other Macs upgraded:
Method 1) Downloading Mountain Lion on Other Macs
The simplest way to upgrade other Macs is to just download the installer on other Macs. From the other computer(s) you wish to upgrade to Mountain Lion:
- Launch the Mac App Store and be sure you are logged in with the same Apple ID that you originally bought Mountain Lion with
- Click on the “Purchases” icon and locate “OS X Mountain Lion”, then click the “Install” button
- Run the installer as usual to upgrade the Mac
Don’t want to re-download OS X 10.8 from the App Store? You can also just copy the installer to other Macs. Here are two simple ways to do this over a network, the easy way with AirPort and the traditional way with File Sharing. The best time to do this is before upgrading the primary Mac so that you have easy access to the Mountain Lion installer without having to re-download it from the App Store.
Method 2) Transfer the Mountain Lion Installer Over AirDrop
If the Macs you’re upgrading are running Lion, using AirDrop to transfer the installer is by far the easiest solution and it will prevent you from having to download the 10.8 Installer app again from the App Store:
- From the Mac you are copying the Installer from: open a new Finder window and navigate to /Applications/ and locate the file “Install OS X Mountain Lion.app” then open another Finder window and select “AirDrop” from the sidebar
- From the Mac(s) you are transferring Mountain Lion installer to: open a new Finder window and choose “AirDrop” from the sidebar
- Drag and drop “Install OS X Mountain Lion.app” to the destination Mac(s) in AirDrop, and accept the file transfer on the destination Macs
- When finished copying, upgrade to OS X 10.8 as usual
For Macs without AirDrop support, use traditional File Sharing described next.
Method 3) Copying OS X Mountain Lion Installer to Other Macs via LAN
In order to do this, you’ll need to have downloaded the Mountain Lion installer and not installed it yet, or else you’d have to re-download Mountain Lion. This solution is best for multi-Mac networks and for those looking to upgrade to Snow Leopard
- On all Macs you wish to copy the Installer to, enable File Sharing by going to Apple menu > System Preferences > Sharing > check “File Sharing”
- From the Finder of the Mac with Mountain Lion installer, go to /Applications/ to find the installer “Install OS X Mountain Lion.app”
- Open a new Finder window and hit Command+K to bring up “Connect to Server”, choose “Browse” and connect to the shared Mac
- Navigate to the shared Macs /Applications/ folder and copy “Install OS X Mountain Lion.app” to it
- Repeat as necessary for other personal Macs
Alternative Multi-Mac Upgrade Methods
These are generally for more advanced users since most require the creation of boot disks:
- Copy the installer to a DVD or USB key – this method on it’s own will not be bootable
- Clean install OS X Mountain Lion with a boot disk
- Manually make a bootable Mountain Lion installer drive out of an extra USB drive or DVD
- Use a tool like Lion Disk Maker to create a boot DVD/USB
Did we miss anything? Let us know in the comments. Happy upgrading!