Quickest way to clean install ML?


macrumors 68030
Original poster
Jan 28, 2009
I'm thinking of upgrading to Mountain Lion, currently have Lion.

I know it's now MAS only so once I've backed up what I want, just iPhoto and iTunes libraries really, what the quickest way to clean install it?

Will I have to install Snow Leopard from disk 1st, then connect to MAS, then install ML?

Also is ML also a "code cleanup" like SL was over Leopard? I'm still unsure wether to upgrade, purely as mines a 2007 iMac



macrumors 68040
Jul 13, 2008
The quickest way to upgrade is to follow Apple's instructions.

A "clean install" involves erasing all your data and reformatting, then installing a new system. Then once that is installed, moving your stuff back from your backup. Speed depends on how much needs to be moved, whether it's on a network backup, etc. Even if you move just a couple things you may still have to reenter passwords, serials, email accounts, etc etc. Only you know how much work all of that is.


macrumors newbie
Aug 18, 2012
My experience with a clean install was quite clean and easy: starting from Lion I had created a separate partition for the Users folder so I didn't need to make a special backup for upgrade (I do have TM backups of course). When installing ML all I had to do was wipe the OSX partition and boot the ML SD card. In ML create a user with the exact same username as previously used in Lion. Restore the symlink to the partition and that was it: all my desktops, spaces, passwords, documents, music were ready and waiting. Opening preview displayed all the windows I had open before shutting down Lion! Can't believe how good the process is compared to Windows.

Important point: if you got iPhoto/garageband/imovie free with lion make sure you accept iPhoto/garageband/imovie in iTunes before wiping lion. They are not included in ML as I've found out…