Reinstall your computer’s original version of macOS (including available updates): Press and hold Shift-Option-Command-R. Reinstall the version of macOS stored on your computer’s built-in recovery volume: Press and hold Command-R. In the Recovery app window, select Reinstall macOS Big Sur, then click Continue. Follow the onscreen instructions. Step One: Boot From Recovery Mode, or an Installer. Your Mac’s Recovery Mode is a treasure trove of useful tools, and it’s the easiest way to wipe your computer and start from scratch. Shut down your Mac, turn it on while holding down Command+R. Your Mac will boot into the recovery partition. If you’re using an older Mac (from 2010. The macOS Catalina upgrade would retain the user data, apps, third-party app data, and so on. If your Mac has inherited some problems, then an upgrade won't be able to fix it. In this case, you can perform a clean installation of macOS Catalina 10.15 from scratch.

How to access and use the Internet Recovery mode on Mac computers?

Apple computers are well-known as stable devices with good performance and hardware specifications. The Mac operating system also includes various self-diagnosis and repair tools. Bear in mind, however, that these features might be susceptible to failure. When built-in tools or software-based solutions do not work, the last and most efficient solution is to reinstall the operating system. All modern Mac computers contain two separate methods to reinstall the operating system (by 'reinstall', we mean installation of a fresh OS X version). You can choose to install the operating system from a startup disk or via Internet Recovery.

In this article, we describe the second method: Internet Recovery to install the operating system version that came with the version of your computer. If your computer was released with OS X Mavericks, using Internet Recovery will install this particular version, while reinstallation from the recovery partition will result in a fresh version of the current operating system. Therefore, if you perform the reinstallation process via the Recovery utility, you will receive the same operating system version that existed prior to reinstallation. The Internet Recovery method is useful if you wish to downgrade the operating system. A big advantage of this method is the ability to bring back the computer to full functionality when software is corrupted. Note, however, that stable internet access is required to perform the reinstallation process via Internet Recovery. An unstable Internet connection can lead to the process crashing and no access to the computer. Therefore, you are advised to use an Ethernet network, rather than Wi-Fi. In this article, we walk through the entire Internet Recovery method.

Table of Contents:

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Requirements to access Internet Recovery Mode

Ensure that the Mac meets the minimum requirements to access Internet Recovery mode. All compatible computers are listed below. Bear in mind that some earlier versions of Apple devices might also use this feature. Apple state that Firmware updates grant access to Internet Recovery mode. If your device is older than the machines listed below, check the Apple firmware updates list here.

• MacBook Pro (13-inch, Early 2011)
• MacBook Pro (15-inch, Early 2011)
• MacBook Pro (17-inch, Early 2011)
• iMac (21.5-inch, Mid 2011)
• iMac (27-inch, Mid 2011)
• MacBook (13-inch, Mid 2010)
• MacBook Pro (13-inch, Mid 2010)
• Mac mini (Mid 2010)
• MacBook Pro (15-inch and 17-inch, Mid 2010)
• iMac (21.5-inch and 27-inch, Mid 2010)
• MacBook Air (11-inch and 13-inch, Late 2010)

If you wish to reinstall the Mac operating system, your network must use DHCP and WPA/WPA security methods. All authentication methods listed below are incompatible with macOS installation via Internet Recovery. If your network uses one of the methods listed, change the setting to a compatible configuration (at least for the purpose of the installation process).

Reinstall Catalina From Scratch

• WEP
• WPA-Enterprise
• Certificate-based authentication / 802.1x
• Proxies (where specific proxy servers must be configured in network preferences)
• Captive Wi-Fi networks (where you click an “Agree” button to access the Internet)
• PPPoE (where there is no router handling the PPPoE connection)

Reinstall operating system by using Internet Recovery mode

When you are sure that the Mac is able to access Internet Recovery mode, there is another important task before installing the fresh operating system version. After a successful reinstallation process, the computer will contain only the default software (which is delivered with macOS). All personal data and applications that you have manually applied to the hard disk will be erased. To protect your personal data, create a backup with Time Machine or similar software. Finally, when you are ready to reinstall the operating system, click the Apple logo in the menu bar at top of the screen and select Restart or Shut Down. Once the system starts booting and you hear the startup chime, hold down the combination of Command, Option (Alt), and R.

Keep holding these keys until the animated globe appears with the message below stating 'Starting Internet Recovery' and 'This may take a while'. Note: If you are using a Mac laptop, use the built-in keyboard to access Internet Recovery Mode, since keystrokes might not register properly on external keyboards.

Next, select the Wi-Fi network. If you are not using an Ethernet network, click the drop-down menu and select the desired network. You must confirm access to a Wi-Fi network by entering the password. Then press Return on the keyboard or click the checkmark symbol on the screen to continue.

After successful authentication to achieve the network connection, the Mac will begin to download a recovery system image from Apple's servers. You will see a progress bar monitoring the status of the download. Depending on your internet connection, this process may take some time. Ensure that the computer is connected to the power adapter.

When the image is downloaded, the OS Utilities window will pop-up, giving access to the usual features, such as Restore from Time Machine Backup, Reinstall OS X, Get help online, and Disk Utility. From this point, the process will be similar to the reinstallation via recovery partition. Detailed information about how to install the macOS can be found in this article.

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Apple is ready to give you a change — the all-new macOS Catalina, available as a free download — so let’s get you all set.

There are two different options on how to upgrade. You can install Catalina over your current macOS, keeping all its data untouched. Or, you can get a fresh start with a clean install. The main benefit of clean installation is that you get rid of the system junk and leftovers which might hamper your Mac’s performance.

Get Setapp to get ready for Catalina

A complete toolkit of utilities that prepare your Mac for macOS Catalina install. Upgrade your Mac in minutes without losing any data.

One way or another, getting Catalina on your Mac is definitely worth a try. Look at the bells and whistles it brings along:

• A renewed iTunes experience — with dedicated apps for Music, Podcasts and Apple TV.
• Simplified porting of iOS apps to macOS.
• Sidecar for using your iPad as an additional screen.
• Major updates of your favorite native apps, including Photos, Reminders, and Find My.

And that’s only a small part of your new macOS experience. If you need more reasons, find a complete review of the new Catalina features here.

Prepare your Mac for the clean install

Reinstall Catalina From Scratch Free

If you’ve seen the new Catalina, you must be excited to get your hands on the installer — we get it. But don’t dive right into the upgrade. Your Mac has to be ready. First thing, check device compatibility. The rules are not much different from the Mojave compatible Macs, except for a few older Mac Pro models that Catalina will no longer support. Here’s the full list:

• MacBook Air (2012 or newer)
• MacBook (2015 or newer)
• MacBook Pro (2012 or newer)
• Mac Pro (2013 or newer)
• Mac mini (2012 or newer)
• iMac (2012 or newer)
• iMac Pro (all models)

Found your Mac on the list? Congrats, you’re on the Catalina team. Just a few more things and you’re ready to install:

1. Get a USB drive with minimum 16GB of free space if you plan to install Catalina on a startup disk.
2. Backup your data and clean away all the clutter.
3. Note that it will take your Mac an hour or two to run the upgrade.

Choose your way to clean install Catalina

As we’ve said before, the healthiest method of clean installing the new macOS is by putting it on your startup drive. It’s your perfect choice if your Mac has a single non-partitioned drive where all the files are stored. Simply backup an entire drive and go ahead with the installation.

Another choice would be to test Catalina on a non-startup drive. If you have a spare drive or your startup drive is divided into volumes, this might be a good option to explore. Especially if you don’t want any files to go away.

Let’s dive into the details of clean installation.

Clean install macOS 10.15 on a startup disk drive

Again, this is the recommended option that will leave you with a high-performing Mac. It involves lots of cleaning and securing your files, though. You can take care of all the data stored on your old OS manually, or by using a few easy utilities. Let’s save your time and see how to do it real quick:

Remove junk from your Mac with CMM X

Download a powerful macOS cleaner to get ready for the Catalina upgrade. All the junk, leftovers and old caches will be gone in a moment.

Step 1. Get rid of the junk

Every ancient app leftover that is hiding somewhere in the depths of your Mac may potentially hinder its performance. That’s not what you want. CleanMyMac X can handle the junk before an upgrade. In one smart scan, the app will spot and remove everything — from outdated caches to file duplicates.

One more important detail, Apple will stop supporting 32-bit applications in the new macOS 10.15. So make sure you get rid of them, too. This will help you see the functionality that Catalina will be missing, and find the right alternatives in advance. In CleanMyMac X, navigate to the Uninstaller tab, filter apps by 32-bit, and click Uninstall. As easy as that. Find out what to do when scratch disks are full in photoshop.

CleanMyMac X is a nice utility to keep on your new macOS, too. In fact, it’s the quickest way to refresh an entire system and remove potential threats before they start affecting your performance. The app is available on Setapp — and so is the backup utility for your Mac we’ll talk about in a moment.

Step 2. Backup your drive

You want the redundant files to go. But you also want the needed files to stay. That’s easy with Get Backup Pro, one of the best backup apps for Mac. Unlike Apple’s native Time Machine, Get Backup Pro has the functionality of creating bootable clones — which gives you absolute peace of mind. In case there’s a tech problem with your Catalina installation, the drive can be recovered at any time.

We encourage you not to ignore the backup process. It will help you roll back at any time with minimum loss. Plus, it’s an easy way to move your files to the new OS in batch.

Read more information about Mac update

Step 3. Create a bootable Catalina installer

Before you clean install Catalina, we have to warn you there might be no going back. First, because macOS 10.15 is truly great. Second, because Apple removes an old macOS installer from the App Store once the new version is out. So if you want to have an exit plan, you’ll have to download Mojave installer in advance.

Here’s how you create Catalina installer:

1. Access the App Store and get the new macOS Catalina.
2. Wait for the download process to finish and click File > Quit as soon as the installer launches. Your installer will be stored in the Applications folder.
3. Connect your USB stick and go to Disk Utilities.
4. In the Erase tab, select Mac OS Extended (Journaled) as your format.
5. Name your USB stick and then click Erase > Done > close Disk Utility.
6. 6. Access Terminal and type the following command (make sure you replace [XXX] with your drive name):sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/[XXX] --applicationpath /Applications/Install macOS Catalina.app
7. Hit Return and type in your admin password.
8. When the process is finished, click Done and close Terminal.
9. Congrats, you’re a Catalina user — now officially.

Step 4. Get Catalina on your startup drive

The final part. Your data is securely backed up, so you can go ahead and erase your startup disk drive:

1. Access System Preferences > Startup Disk and choose your Catalina installer.
2. Restart your Mac and hold Command-R.
3. Connect your bootable USB.
4. In the macOS Utilities window, click Reinstall a new copy of macOS.
5. Click Continue and agree to the terms and conditions.
6. Select your startup drive and click Install.

Once the new macOS gets on your Mac, it will be born anew. So yes, you will have to set it up — just like a new Mac. If you’ve used Setapp on the old macOS, you can quickly get your apps back by downloading the installer on setapp.com.

Clean install macOS 10.15 on a non-startup disk drive

If you don’t have a free, non-partitioned drive, you can install Catalina on a non-startup drive. Here are three easy steps:

Step 1. Erase your non-startup drive

If you install Catalina on a new drive, this is not for you. Otherwise, you’ll have to wipe everything away from the drive before using it. Navigate to Disk Utility, select your non-startup drive, and click Erase. If there’s any data you want to keep, use ChronoSync Express to sync it with another drive.

Step 2. Download the Catalina installer

Access your Mac App Store > Updates and grab the installer. Once the installer will launch automatically, quit — you don’t want to install it from there.

Step 3. Install Catalina to your non-startup drive

You’ll find the downloaded installer in your Applications folder and launch it. Select a drive — you’ll have to change it from “startup” to your target one. Follow the instructions and finish your installation.

Once your system is upgraded, set up your new Mac and make sure you try all the perks. And before you get frustrated that your favorite 32-bit app is missing, get Setapp — it surely has a decent alternative.

If you are a true macOS fan, check out the comparison of iOS and macOS adoption trends below:

How Do I Reinstall Catalina

Reinstall Macos Catalina From Scratch