Clean Install macOS Catalina Using Internet Recovery Method. Power down your Mac completely. Power your Mac back on and hold down the Command + Option + R keys until you see a. Changes introduced with macOS 10.15 (Catalina) cause certain Java applications to behave incorrectly. Therefore, we cannot certify any JDK version on macOS 10.15 yet. However, as of now, you can install and run non-notarized software on macOS 10.15 systems by modifying your security preferences. Detailed information and steps are available here. Download Hackintosh Catalina Installer: Catalina Installer is a distribution of macOS Catalina that has been made to work with PCs. You will need to use a BitTorrent client to download the disk image file containing Hackintosh Catalina, which is a little less than 6 GB in size. You must register on the website to be able to download anything.

• MacOS Catalina (10.15) The sixteenth big update of macOS, Apple Inc.’s desktop operating system for Macintosh computers, is called Catalina.It is the successor to macOS Mojave and was unveiled on June 3, 2019, at WWDC 2019 and launched to the general public on October 7, 2019.
• MacOS Catalina Setup Process. Agree to the macOS Catalina License agreement. Select macOS Catalina Disk and click Install. Agree to the Terms and Conditions. Select Installation Disk for Catalina. Now, wait for 3 minutes and your VM will restart. MacOS Catalina will be installed on your Disk.

Attempting to download macOS Catalina from the Mac App Store you may find that a small version of the “Install macOS Catalina.app” file downloads to the “Applications” folder, rather than the complete 8.1 GB installer file.

The tiny (just tens of megabytes) incomplete installer requires an internet connection during usage to download the rest of the Catalina update files. Additionally, it does not allow to create a macOS Catalina USB installer drive for use on multiple computers.

In this tutorial, I’ll show you how to download the complete “Install macOS Catalina.app” file from Apple server using the “macOS Catalina Patcher” app instead of via the Mac App Store.

A similar mini-installer issue occurred previously with some users getting a tiny incomplete macOS High Sierra installer and macOS Mojave installer too and I covered a similar workaround here and here to download the complete installer file from Apple server.

About the app

In this workaround, we’re going to use the macOS Catalina Patcher app from the dosdude1.com. This app is intended for those with unsupported Macs and Hackintosh users, but any Mac user can use the app to be able to download the complete macOS Catalina installer file from Apple server. For our purposes in this particular walkthrough, we will use the app only to download the complete installer file.

Note! This method relies on a third party app from an unverified third party source. If you are not comfortable with using unvetted and unverified software, do not follow this process.

Let’s begin

Downloading the complete “Install macOS Catalina.app” file from Apple server using the “macOS Catalina Patcher” app is a really easy process. Now, step by step guide.

Go to the official website of the “macOS Catalina Patcher” app here and download the app.

The download link is labeled as “Download Latest Version” on that page.

Launch the “macOS Catalina Patcher” app.

Note! By default, macOS preventing apps from unidentified developers or sources from being launched. So you most likely will get an alert message that says: “macOS Catalina Patcher.app can’t be opened because it is from an unidentified developer”. To allow just one specific app to run do the following:

1. Hold down the Control key and click the app icon. From the contextual menu choose Open.
2. A popup will appear asking you to confirm this action. Click the Open button.

Click the “Continue” button, and then select “Download a Copy”.

Confirm that you want to download the “Install macOS Catalina.app” app to start the download to your hard drive.

Close the “macOS Catalina Patcher” app when the download is complete and locate the “Install macOS Catalina.app” file you downloaded.

Note! The download will be completed when you are prompted to choose an installation method. See the screenshot below.

Conclusion

That’s it, you’re done. Now you have the complete “Install macOS Catalina.app” file downloaded. So simple isn’t it?

You can confirm that you have the complete “Install macOS Catalina.app” file by getting info on the file. For this simply select the file and click the Spacebar key (or right-click on the file and choose “Get Info”). The complete installer should be around 8.1 GB rather than the tiny (just tens of megabytes) incomplete installer that requires additional downloads.

Note! Remember, the “Install macOS Catalina.app” file deletes itself automatically after macOS Catalina has successfully installed. Therefore, you may want to make a backup by having previously copied it to external storage.

Let me know in the comments section if you know another way to download the complete “Install macOS Catalina.app” file rather than the tiny incomplete installer.

I hope this article has helped you learn how to downloaded the complete “Install macOS Catalina.app” file from Apple server. If this article has helped you then please leave a comment

Thanks for reading!

Arthur is a designer and full stack software engineer. He is the founder of Space X-Chimp and the blog My Cyber Universe. His personal website can be found at arthurgareginyan.com.

Summary: This page is about how to reinstall macOS in macOS Recovery mode. Based on if you want to keep the original data on the startup disk, you can either choose to clean reinstall macOS or to reinstall macOS without data loss.

Reinstalling macOS gives your Mac a fresh start especially when you are frequently bothered by some issues, such as Mac not turning on, Mac hanging on the beach ball, apps frozen on your Mac, slow performance, or pink screen on Mac. Most of the time, such issue results from some system-level problems, while reinstalling macOS can easily save your life.

• How to reinstall macOS on an M1 Mac?

How to reinstall macOS from macOS Recovery mode?

When you need to reinstall macOS on your Mac, macOS Recovery mode makes this process easy and quick. By the way, if you want to learn more about macOS Recovery mode, you can watch this video.

To reinstall macOS in macOS Recovery mode:

Step 1: Make sure your Mac is connected to a stable Internet within all the following steps.

Step 2: Identify it's an Intel or M1 Mac, and immediately do one of the followings.

• Press and hold Command + Option + R.This allows you to reinstall the latest version of macOS that is compatible with your Mac computer from the internet.
• Press and hold Shift + Command + Option + R. This option allows you to reinstall the macOS that came with your Mac, or the closest version still available.
• Press and hold Command + R. This allows you to reinstall the version of macOS stored on your built-in recovery disk, including any updates that you installed.

• How to Boot into & Use M1 Mac Recovery Mode

Step 3: Release these keys when you see an Apple logo, spinning globe, or the Utilities window.

Step 4: Enter the requested password if you are prompted to enter a firmware password or the administrator's login password.

• Recover/reset your forgotten Mac password

• Mac won't accept correct password, what to do?

Step 5: Decide if you want to clean install the system, or just reinstall macOS without losing your original data.

If you want to factory reset the Mac for selling or giveaway, or the startup disk becomes corrupted, you might want to erase the startup disk before reinstallation. This guarantees a fresh and clean installation as it wipes all your personal data on the disk.

• How to factory reset your Mac?

• How to reset your M1 Mac to factory settings?

If you only want to reinstall macOS because the original operating system is not working as you expect, you might want to keep your personal data intact. In case files are deleted or lost by accident during macOS reinstallation, you should have a backup of your data or getting files off first.

• How to get files off a MacBook that won't turn on?

Step 6: Either after erasing the startup disk or getting files off the Mac, you can then go back to macOS Utilities and choose Reinstall macOS. Check this post to find all macOS versions and know which one you are going to reinstall.

Step 7: Follow the on-screen instructions and choose a disk to reinstall the OS.

• If the internal startup disk is not showing up, or the installer says that it can't install macOS on your computer or volume, you might need to back up files and then erase your disk.
• If the installer asks you to choose Macintosh HD or Macintosh HD - Data when installing macOS Catalina, choose Macintosh HD.

Other ways to install macOS

Apart from reinstalling macOS from macOS Recovery mode, you have other options according to your situations.

1. Get released macOS versions or updates by App Store or Software Update preferences.
2. Get macOS beta (such as macOS Monterey that might be buggy now) through Apple’s developer website.

Install Catalina On Unsupported Mac

Whatever your situation of reinstalling macOS is, you should always retrieve your data from the Mac before any further movement. After all, you can't tell if you want it back or not in the future.