Reinstall Mac OS X

Reset MacBook iMac Mac mini & Pro

Today I’ll show you how to do a clean install of your Mac operating system, i.e. how to reset OS X:

The easiest way to reset or reinstall is via the built‑in recovery function on the Mac. Some of you have probably already used this feature. Here’s how it works:

The recovery function is started using the Command (CMD) key and the R key. Both keys must be pressed simultaneously when turning on the Mac. (Note for Apple Silicon the key combination does not work on these devices).

If the Mac is not yet connected to the internet, you now need to establish a connection.

Once the connection is established, a recovery symbol appears. If an internet connection is already available, the recovery symbol is shown immediately.

Now click the recovery icon to start the restoration. 

Note: only for devices with Apple Silicon M CPU:

Note for Apple Silicon M1, M2, M3, M4, M5 devices: Turn on the Mac or open the lid and hold down the power button until the startup options window appears. Click the gear icon labeled "Options" and then click "Continue."

In Recovery Mode:

If you want to keep your data and only do a clean reinstall of the operating system because you suspect an error, then after selecting the language you can start the installation right away. Simply click Reinstall macOS and confirm with Continue.

Then select the drive you want to install to and confirm again. 

If you want a completely fresh installation without any data, you must erase the drive beforehand. So first click Disk Utility and then confirm with Continue.  

In Disk Utility, select the drive you want to erase in the left column and confirm by clicking Erase.

A window will now appear where you can enter a name for the drive.

If everything is correct, confirm here to erase.

Once the hard drive has been erased, you can close Disk Utility. Just click the red X.

You can now start the installation, exactly as described above:

Click “Reinstall macOS” and confirm with Continue.

Then select the drive you want to install to and confirm again. 

This guide works for all Macs such as MacBook / Pro / Air, Mac mini, Mac Pro, iMac from model year 2011 onward.