Something that you may need to do from time to time is to completely clean off a Mac.
This may happen if you're trying to resell it or pass it along to somebody else.
You want to get all your stuff off there and give them a Mac that's just like new.
So the first thing you want to do when doing that is make sure you are signed out of everything.
For instance, look in Messages, look in FaceTime, look in iTunes, look in the App Store.
Look everywhere you can think of and sign out and delete accounts.
Go into System Preferences, make sure you've turned off all your iCloud services and you've
removed your iCloud account.
You can see I've done that here.
Nothing there.
Under internet accounts make sure you've removed all your internet accounts.
You can be signed in for things like Twitter, Facebook, etc.
Make sure they're all gone.
Go into Mail and make sure they're all gone.
Clean everything off.
If you're using Cloud services like for Microsoft or Adobe make sure you are logged out of that.
All those applications.
Make sure everything's good and you won't have anything hanging around on this machine.
For instance, you don't want to have the iMessage system still thinking this machine is something
that should be sending messages.
You want to make sure you are signed out of everything.
The only thing that you want to keep around is WiFi.
You don't want sign out of WiFi because to use the internet recovery function, which
is how we are going to clean the Mac off, we are going to have to use the WiFi so we
can contact Apple and not only load in utilities that will help us clean off this Mac but then
reinstall the system clean and fresh.
So what we want to do now is enter internet recovery mode which will instead of loading
the operating system from your drive will actually load the operating system or a simplified
version of it from the internet, from Apple so it will allow us then to clean off the
drive and reinstall the system.
To do that we are going to restart and when we restart as soon as we hit this button I'm
going to hold down the keys Option, Command, and R. That will put us in the internet recovery
mode.
I'm holding down those keys here and in a second you will see it show that we're doing
internet recovery mode.
That's what we're doing now.
It's going to take awhile for it to load the operating system remotely so it's a good time
to get a cup of coffee, have a meal and come back when it's ready.
So once it's done, and it took me about twenty minutes with a pretty fast internet connection
for it to load this version of the operating system and present me with this screen.
Once it's done the next step that you want to do is you want to choose from Utilities
here Disk Utility.
So I'm going to choose Disk Utility and Continue.
This will allow me to erase the drive.
So I can see here, here's my Macintosh hard drive.
This other thing here, this OS 10 base system, that's what it just downloaded.
Basically downloaded a temporary version of the operating system for me to be able to
do this while I'm not using the hard drive.
I'm going to select Macintosh hard drive and then here I can now erase the drive completely.
I can do that by selecting the Mackintosh hard drive under Mackintosh hard drive, the
volume itself.
Go to Erase.
I need to choose Mac OS extended journaled.
Then hit Erase.
That will completely erase the hard drive while at the same time still remaining here
inside this utility since this utility is kind of, you can think of it as running in
memory rather than running off the hard drive itself.
Then once it's done erasing I have a completely empty hard drive but I'm still in this special
mode where I can do other things.
So once the erasing is done I can quit disk utility and it's going to take me right back
to the screen here.
Now I can go and select Reinstall OS 10.
Now notice it says OS 10 not Mac OS as in Sierra Mac OS but OS 10.
That's because when I bought this MacBook it was El Capitan what was the most recent
version of the operating system.
So when I reinstall the OS it's actually going to reinstall El Capitan from Apple servers
putting this machine back into factory original state.
I can start that by hitting Continue.
Then the process will take a long time to download the operating system, reinstall a
fresh copy on this blank disk.
The first screen that I'll see after that is a screen asking me to setup my Mac.
You don't want to do anything.
You don't want to type anything, you don't want to enter anything.
You don't want to click on anything.
As soon as you see that screen saying that it's time to setup you're Mac then immediately
use Command Q to quit the setup.
Then immediately shutdown the Mac.
What this does, is basically when you start the Mac up again next time, it will start
up in that setup mode which is what you want to happen when you give the Mac to somebody,
whether you've sold it or given it away, they'll get it just like they took it home from the
Apple store asking them to setup their Mac.
It won't have your Apple ID on it.
It won't have any of your accounts on it.
It'll be just like they bought it and it's brand new.
That's how you want to setup a Mac for selling it or giving it away.
Tomorrow I'm going to show you how to do this if you're not actually giving it away or selling
it.
Maybe you just want to clean it off for yourself or maybe you want to give it to someone who
is trusted like a child in your family or sibling or something like that.
In that case you may not want to reinstall the original operating system that came with
it.
You may want to install the most recent operating system, in this case Sierra, and it's a little
bit easier to actually do that.