I have a very nuanced question about how to setup a Mac that I'm hoping someone can help me with. I just sold my mid-2012 15 inch Retina MBP to someone and they are wondering the best way to go about transferring their current system (data, apps, etc..) to the new MacBook Pro. Here are the key details...and the "nuance"! For the MacBook Pro that I sold them (i.e. The target laptop): I used Internet Recovery to load OS X Mountain Lion back on it (i.e. The original version of OS X that came with the MacBook Pro). The current Macbook the person who bought my MBP owns (i.e. The Source laptop): It's a 2009 Macbook (i.e. Not a pro). They have done a time machine backup of it. It's currently on El Capitan My question: When they first launch the new 15 inch MBP (i.e. With a fresh install of Mountain Lion): Can they simply use "Setup Assistant" to transfer all of their data, apps, settings, etc... from their Time Machine Backup....even though their Time Machine BU was done using El Capitan? Is it possible to use setup assistant when the source backup (i.e. Done on Time Machine) is on a latter version of OS X than that of the target machine (i.e. The new MBP). Or, will they have to use Migration Assistant (i.e. Later) to transfer their data, apps, settings, etc... from their time machine backup. I'm thinking this is the case. Am I correct? If so, I'm assuming these are the steps they would need to follow: Setup the new MBP as a clean installation (i.e. Not using setup assistant to build it from a Time Machine BU), but plan instead to use migration assistant later. Be sure "NOT" to name the new account (i.e. Created in the setup process) the same name as the old account that will be migrated later via Migration assistant. Upgrade the OS X to Sierra on the new MBP before using Migration assistant. Use Migration assistant to transfer all data, apps, settings, etc... from the existing time machine bu of the old machine (i.e. Currently on El Capitan). Thanks in advance.