Backup before updating to mountain lion
However, some have found a way to get it to work with both.
If you have issues with the download after reading the rest of this tip, please contact the Mac App Store form or e-mail, to ensure you don't get double billedwhen you redownload Mountain Lion.
Times may vary by speed of the hard drive, connected peripherals (preferably none), available disc space, and available RAM.
Unlike Lion, before the installer begins, it leaves behind a distinct 4.3 GB installer file you can drag to any backup you need before beginning with the 36 minute installation process.
If you want to go through a formal way, submit a bug reportafter signing foran online developer account.
A clone backup, explained in the "backing up" link in the prior sentence, prior to upgrading to Lion will ensure you are able to backstep to Lion in event you don't have a USB Flash drive copy of Lion.10.2 & 10.3 are not mentioned above since they can't be upgraded to 10.6 or later.Before updating to 10.7 or later from 10.6.8 or earlier, please read this tip:https://discussions.apple.com/docs/DOC-627110.9, and 10.10 are no longer available, unless it was preinstalled on your Mac or you purchased it prior on the Apple Store.For the latest security updates see searching for the newer one together with the textsupport.DLwill get newer download links.Mavericks is mentioned on this same line, as the Apple hardware requirements are the same, though the compatibility for Mavericks for third party devices may differ.