How Long Does It Take to Reinstall Mac OS From Scratch?

Reinstalling macOS is needed if you are finding technical glitches on your Mac. Also, when you are planning to sell or give away your computer, remove all the traces of data. When you need to improve the overall performance of your computer, reinstalling the operating system is the best solution. 

Optimizing your Mac by reinstalling macOS is not a big task; what concerns users is how long does it take to reinstall Mac OS, as it impacts the workflow. 

Why Is macOS Reinstall Needed?

When you reinstall the operating system, it rewrites each line of code. Reinstalling the macOS will not change the existing version; indeed it installs the same version of the operating system from scratch. 

The entire process will not remove any data from your computer; however, we recommend you backup your computer to avoid data loss. Having said that, you will find all the files, documents, apps, programs, and settings intact. 

If you intend to delete any data permanently before selling your computer, you must be searching about how to wipe a MacBook. In that case, use Disk Utility to erase your computer’s hard disk. 

Wiping the hard drive is a straightforward process; you need to be careful, though. Read onscreen instructions carefully for proper execution. That’s why we recommend backing up the computer regularly so that you can restore data in case you need it back.  

How to Reinstall macOS?

To reinstall macOS on your Mac, you need a fair share of time and a reliable internet connection. Apart from that, you need macOS Recovery, which is a special mode inside your Mac you can boot into during the reinstallation procedure. 

Before you initiate the reinstall process, make sure your WiFi connection is secure. What does that mean? Well, a secure WiFi is WPA or WEP password protected. Most home WiFi connections are already WPA protected. 

Users often ask how long does it take to reinstall Mac OS; the answer is anywhere between 30 minutes to a couple of hours. So, if you have a pending project with a close deadline, try to complete it to avoid delays. 

Now, let’s move on to the steps to reinstall macOS. 

Step 1. Find Out If Your Mac Has Intel Processor or Apple Silicon 

To reinstall the operating system, you need to boot your Mac into macOS Recovery mode. The process you follow depends upon the processor chip your Mac integrates. To simplify this, first, you need to figure out if your Mac runs on an Intel chip or Apple Silicon. 

To identify the processor, navigate to the Apple menu and select About This Mac, displayed in the top-left corner of the menu bar. You can see the specification of your computer in the About This Mac window. 

If the specifications say Chip followed by chip name, your Mac runs on an Apple Silicon M1 chip. However, if it says Processor followed by processor name, the Mac runs on an Intel processor. 

Step 2. Boot Into macOS Recovery Mode

Once you identify if your Mac runs on Intel processor or Apple Silicon chip, the next step involves booting the system in macOS Recovery mode. Before you proceed further, back up your Mac so that you can regain access to data if anything goes wrong. 

Now, click on Apple and select Shut Down. Wait for the Mac to turn off normally. Once your Mac shuts down properly, follow the steps mentioned below based on the type of processor your Mac runs on. 

If your Mac has an Apple Silicon chip, press and hold down the Power button to turn it on. Keep holding the Power button unless you see the Startup Options window. Click the Options button and click Continue to proceed further. 

If your Mac runs on Intel Processor, here’s what you need to do next. Press the Power button and then immediately press the Command + R keys simultaneously. Keep holding the key combination until the Mac turns on, and release the keys after you see the Apple logo. 

When the system prompts, select a user account and sign in with your Mac’s administrator password. You will then see the macOS Recovery window on your Mac screen. Operating system reinstallation is required for maintaining the good health of the device even if you are using the best computer

Step 3. Reinstall macOS

On the macOS Recovery screen, you will see a couple of options, including one that says reinstall macOS. If you need to erase the hard drive first, click Disk Utility and select to erase the Macintosh HD Data partition on the startup disk. 

If you don’t want to erase the partition on the startup media, select the Reinstall macOS option. Follow the onscreen instructions carefully to download and reinstall macOS on your Mac. You may also need to enter your Mac’s administrator password.

Keep your Mac switched on and awake while the macOS reinstallation is in process. That means you must not turn it off or close the MacBook’s lid, as it will interrupt the process. When the macOS reinstallation process completes, the Mac setup screen appears.