How to install Lion or Mountain Lion on multiple computers
If you've purchased OS X Lion or Mountain Lion from the Mac App Store, you're allowed to install it on all of your personal authorized Macs.
To install OS X Lion or Mountain Lion on another Mac, open the Mac App Store, sign in to your account, and re-download the OS by selecting it in the Purchases list. Follow these steps:
- Download Lion or Mountain Lion from the Mac App Store on one of your personal authorized Macs. The download is approximately 4 GB in size.
- Install the OS.
- Log in to another computer that you wish to install it on.
- Open the Mac App Store. Enter your Apple ID and password that was used to download either Lion or Mountain Lion on the first computer.
- Click the Purchased icon, then click the download link for the appropriate OS.
- Run the Installer once it has finished downloading to the new Mac.