My wife’s laptop (2009 Alum. MacBook) was still running OS X Leopard, and the lack of performance and support was getting pretty annoying. Finally, I took the effort to install the latest Apple OS on her laptop. When running Leopard, there is on complication: Mountain Lion can only be bought in the App Store, and Leopard has no App Store.
The official Apple way of solving this is to first upgrade to Snow Leopard, and then use the App Store to buy and install Mountain Lion (ML). I did not want to do this for two reasons: I wanted a clean install, and I did not want to first upgrade to Snow Leopard. The following steps describe what I did to do a single step, clean install of Mountain Lion. Do note that this howto requires another Apple computer with Lion/Mountain Lion already installed, I will refer to this as the other machine.
- Backup you data before following these steps as you will wipe the Leopard device’s hard drive. I would recommend not using a full backup such as Time Machine, but copy your homedrive to an external drive. A full backup will also backup and restore all kinds of old Leopard stuff. With a backup of your homedrive, you can then selectively copy back data such as photo’s.
- Acquire Mountain Lion. If you already have ML, and the device you want to install it on is going to use your Apple ID, you do not need to rebuy ML. If, as in my case, the other computer is going to run under another Apple ID, you need to take the following steps:
- Open the App store on the other machine,
- log in with the Apple ID for which you want to buy ML
- buy ML. Note that ML will start downloading immediately, you can cancel this right now.
- Create a recovery USB drive using the Recovery Disk Assistant that Apply provides. This needs at least 1GB of space.
- Insert the USB drive into your Leopard device, and restart. During the boot sequence, press the Option key (alt) to gain access to the boot menu. Select the USB drive as boot device.
- Once you’ve booted into the Recovery Assistant, go to the Disk Utility and wipe the boot partition (not the hard drive itself) on your hard drive.
- Connect to your WiFi network or insert your network cable.
- Go back to the main menu, and select the option to install ML. You will be asked to enter an Apple ID, enter the one relevant for this old Leopard device. This was my wife’s ID in my case. The Recovery Assistant will now download ML (can take some time, as it is 4.4 GB), and run through the installation procedure. This took around 3 hours for me. The machine will automatically reboot, and you will enter Mountain Lion heaven…
– Do note that iLife with not be available after installing ML from scratch. You can, however, install iLife from the original installation DVD’s you got with your Apple device. You will get the old iLife version, the new, updated ones need to be purchased in the App Store if you follow this guide.