Then click on the three dots to browse the macOS Catalina DMG and select it. Select DMG File. Choose the macOS Catalina DMG and click on OK. Ok Restore Disk Image to Drive. Hit Yes on the pop and it will start creating the USB so it will take a considerable time. Unibeast is a tool for Hackintoshes to create Bootable USB for macOS operating system from an install of macOS X Lion App, Install macOS Mountain, Install macOS Sierra, Install macOS High Sierra, Install macOS Mojave, Install macOS Catalina. This is an all-in-one Bootable USB drive also used as a rescue boot drive for system recovery. 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.

If you want to use your USB stick with an Apple Mac, you will need to restart or power-on the Mac with the USB stick inserted while the Option/alt (⌥) key is pressed. This will launch Apple’s ‘Startup Manager’ which shows bootable devices connected to the machine. Your USB stick should appear as gold/yellow and labelled ‘EFI Boot’. How to create a bootable macOS Big Sur USB install drive. Step 1: Download macOS Big Sur. After Big Sur launches later this year, you’ll be able to download it directly from the Mac App Store.

It does not matter whether you use macOS or Windows 10. It’s just a matter of time until your device will refuse to start, which could happen for many reasons, including (and not limited to) file corruption, hardware failure, and buggy update. If the unexpected happens with an Apple computer, you can use a macOS bootable USB with the installation media to repair it.

Create Bootable Usb On Mac From Iso

This is one of the main reasons you should consider making a macOS bootable USB when your device is working properly. However, if none of your devices (MacBook, MacBook Air, MacBook Pro, iMac, Mac Pro, or Mac Mini) aren’t working when you need them the most, then you can use a PC to rescue your Apple device. You can use a Windows 10, Windows 8.1, or Windows 7 device to quickly create a USB bootable installation media to reinstall macOS Catalina or Big Sur on your Mac.

In this guide, you’ll learn the steps to create a macOS Catalina bootable USB installation on Windows 10, which you can use to reinstall or upgrade the Apple OS.

Requirements

Before proceeding, you’ll need the following:

• Broken Mac computer running macOS (version 10.12, 11, or later).
• A trial copy of the TransMac software.
• One high-quality USB flash drive with 16GB of storage.
• Copy of macOS (DMG file).

Create macOS bootable USB installation media

To create a bootable USB drive with macOS, use these steps:

1. Download and install TransMac on the Windows 10 device.

   Quick note: This is a paid software, but it gives you a 15-day trial, which is more than enough time. (If this works for you and you want to support the developer, you can purchase the full version.)

2. Connect the USB flash drive. (If you have any data on the flash drive, remember to make a backup, as everything on it will be erased.)

3. Right-click the TransMac app and select the Run as administrator option.

4. Click the Run button. (If you’re using the trial version, wait 15 seconds.)

5. Right-click the USB flash drive, select the Format Disk for Mac option from the left navigation pane.

   Quick note: You want to do this before creating the bootable media because there is a good chance that the drive was formatted using a Windows device. If this is the case, the chances are that it’s using an MBR partition, and the USB drive needs a GPT partition to work on a Mac.

6. Click the Yes button to format the drive on the warning message.

7. Confirm a name for the drive. For example, “macOS bootable USB.”

8. Click the OK button.

9. Click the Yes button.

10. Click the OK button.

11. Right-click the USB flash drive and select the Restore with Disk Image option from the left navigation pane.

12. Click the Yes button to confirm the erase of the USB flash drive data.

13. Click the browse button on the right.

14. Select the .dmg file with the macOS installation files.

15. Click the Open button.

16. Click the OK button.

17. Click the Yes button.

Once you complete the steps, you can now insert the USB flash drive on your Mac computer to install, reinstall, or upgrade the operating system to the latest macOS version, which can be Sierra, Catalina, Big Sur, or higher.

Create a GPT partition on USB flash drive

If the USB flash drive is not working with TransMac, it could still be a partition problem. In this case, you may need to redo the entire process again. However, this time you should use the following steps to use the Diskpart command-line utility on Windows 10 to create the appropriate GPT partition, and then follow the above instructions.

To create a GPT partition on a removable drive, use these steps:

1. Open Start.

2. Search for Command Prompt, right-click the top result, and select the Run as an administrator option.

3. Type the diskpart command and press Enter.

4. Enter the list disk command to view all drives connected to your computer and press Enter.

5. Type the select disk command followed the number assigned for the USB flash drive (for example, select disk 4), and press Enter.

6. Enter the clean command and press Enter.

7. Type the convert GPT command and press Enter.

8. Enter the create partition primary command and press Enter to complete the process.

Once you formatted the USB flash drive with a GPT partition, you can use the instructions mentioned above to use TransMac to create a bootable media, but this time skip steps No. 5 through 10 and continue on step 11.

After the process completes, which can take up to an hour, connect the USB flash drive and power on your Mac holding down the Option key, select the USB drive to begin installing macOS.

If you have problems creating the bootable media, you can get a USB flash drive that comes with macOS Sierra, El Capitan, Catalina, etc., on it with the link mentioned below. (I haven’t tried it personally, but it’s worth the try if nothing works.)

If your Mac suddenly refuses to boot up properly, you might need a bootable macOS USB installer to make repairs. But how do you create such a disk if all you're left with is a Windows 10 computer? Fortunately, there's a great tool that you can use for free to create bootable macOS media on a USB drive in a Windows 10 environment. This article shows you how to download a macOS DMG file, format a USB drive using a GUID Partition Table, burn the DMG to the drive and boot your Mac from the USB. All the steps except the last one are done on a Windows 10 machine.

Part 1: Download macOS or Mac OS X DMG File

The first step is to get the DMG disk image file for the version of macOS that you want. You can get a copy of the latest macOS version from Apple download portal or App Store here. There are also several other direct download sites that offer various versions of Mac OS X in DMG format rather than the standard APP format that runs on Mac. Since you're working in a Windows environment, you need the DMG rather than the APP file.

macOS DMG Download Link:

Part 2: Format USB Drive to GPT (Optional)

Updates (Dec 8, 2020): The latest version of UUByte DMG Editor is able to format the USB automatically, so this part is optional. Follow the steps only when the burning process failed in Part 3.

Create Bootable Usb On Mac Disk Utility

Mostly, the USB drive was formmated to FAT32 in default when being shipped out from the factory. However, FAT32 can be only used for installing OS with legacy BISO, which doesn't work for macOS. So the next step is to format your USB drive in the GPT partition style in order to burn installation files to the desired USB drive. You can do this in Command Prompt as admin. In elevated Command Prompt (Ctrl+Shift+Enter), input the following series of commands followed by Enter after each line:
Diskpart
List disk
Select Disk X (X stands for the USB drive name that appears after the previous command)
Clean
Convert GPT
Create partition primary

Part 3: Create Bootable macOS USB from Windows 10/8/7 PC

You have now formatted the partition of USB drive. It's time to download UUByte DMG Editor for Windows. Although this is a premium software, you can use the initial free trial period to create a bootable macOS USB on Windows 10. After installing the application, follow the sequence of steps shown below:

Create Bootable Usb On Mac For Windows

Step 1: Right-click the software icon on desktop and select 'Run as Administrator' from the contextual menu. Choose 'Run' when prompted.

Step 2: Insert your formatted USB drive, and click 'Burn' tab on the main screen.

Step 3: Click 'Browse' button to import macOS dmg file into the program. And select the USB drive name from the second row. You can also set a volume labe for that USB drive.

Step 4: Click 'Burn' button at the bottom to start the process. You will see a progress bar and wait around 10 minutes to get it done.

Step 5: Once the progress bar is at 100%, a bootable macOS USB is ready. After that, you can use that USB drive for installing macOS.

This is one of the easiest way to create a bootable macOS USB on a Windows PC. The steps are simple and instructions are pretty clear.

Part 4: Boot Mac from macOS USB Drive for Installation

Now remove the USB drive and insert it into the Mac computer. To boot from the disk, you need to hold down the option key when you hear the boot chime. This will take you to the Startup Disk Manager, where you should be able to see the USB drive. It might have a different name, but as long as it is bootable, you'll be able to see it there. Once you select it, the computer will boot from the disk and the macOS installation will begin.

Conclusion:

Create Bootable Usb On Macos Catalina

How To Install Catalina From Usb

The whole process might look a bit complicated if this is your first time, but just follow the instructions in this article and you should be fine. That being said, you need to be careful when downloading the DMG file and formatting your USB drive. If you don't do these two steps correctly, the output drive from the UUByte DMG Editor software won't be bootable, which means you can't install macOS from that USB drive, and you may need to do the whole thing over again.

Customers get Software upgrades for Mac computers through the online app store ever since the release of macOS Lion. Be it a clean install or upgrade, Mac App store require you connect to the internet to download whole installation files. The online OS update is OK if you have stable broadband connectivity and enough bandwidth. Apple also provides an option for internet recovery of macOS if your computer fails to boot. But there are situations where you can’t download the OS from the Apple servers. Having a macOS offline installer or a bootable USB disk is the only solution in such scenarios.

Download macOS offline Installer

Installing macOS without internet requires a bootable USB disk. And you need to download a full-size macOS installer for making this disk. Hence, before anything, we will tell you how to download macOS offline installer directly from Apple to your Mac using a GitHub script.

Download the gibMacOS script from this link and extract it to your Mac. From the extracted folder, run the script called gibMacOS.command — it will open the Terminal as shown below.

Wait for the script to fetch the macOS download catalogue from Apple. When the list is ready choose a number as per your OS option and press the Return/Enter key. You can use this script to download macOS Big Sur (11.1), Catalina (10.15), Mojave (10.14), and High Sierra (10.13.6). A new folder “macOS downloads” appears in the “gibMacOS-master” as you provide a download option, and the OS starts downloading as you can see in the video.

The OS gets downloaded as parts, PKGs, DMGs and other files. For macOS versions up-to Big Sur, you need to use another script “BuildmacOSInstallApp.command” in the main folder to join all the downloads and make the full macOS installer app. All you need is to drag and drop the downloaded macOS folder to the terminal window. The script will build the offline installer and save it to the same folder.

You don’t need to use the second script if your choice is macOS Big Sur. Because, for macOS Big Sur you get a full-size installer from Apple in PKG format. Double-click and open the InstallAssistant.PKG to save the “Install macOS Big Sur.app” to the Applications folder.

Apart from this, some older versions of macOS are available for direct download from Apple (Sierra, EL Capitan, Yosemite) in DMG format.

How to make a macOS bootable USB installer

It is possible to create a backup macOS installer on a DVD or USB drive but later is the best choice. Most of the Macs these days don’t have DVD slots, and the installation through a disc is very slow. Hence we discuss only about making macOS recovery installer on a USB disc. For this you need a Mac and a USB pen drive of at least 8 GB space, and a third-party app called DiskMaker.

1. First, download a copy of Disk Maker from the official website.
2. Choose a version as per your requirement. For example, if you want make USB installer for macOS Catalina 10.15, download Disk Maker X 9.
3. I use an MacBook Pro with High Sierra. Hence, I’m downloading disk maker X 7.
4. The next step is to download full macOS installer from the App Store to your Applications folder.
5. Run Disk Maker DMG installer and copy the app to the Applications.
6. The application will automatically detect the downloaded macOS as shown in the screenshot. Select “Use this Copy” if you would like to proceed with it.
7. Next is setting the USB pen drive for creating the bootable installer. Choose the third option ” An 8 GB USB Thumb drive.”
8. The app will list all drives in your system. Pick the one you would like use as macOS USB installer.
9. Ignore the warning message and proceed to Erase and Create macOS USB disk. Don’t forget to provide your admin password when it prompts.
10. Keep checking notifications tab for progress. When it completes you will find Install macOS Mojave (or High Sierra) mounted to your desktop as a USB disk.
11. That’s your backup. Unmount and keep the USB installer to a safe place.

Install Mac Os Catalina From Usb

Unfortunately, the above app is not compatible with macOS Big Sur 11 and above. Check the instructions on Apple website, the manual method to make macOS offline USB installer.

Install Catalina Os From Usb

What is the alternative if I don’t have usable Mac at the moment?

This method is applicable when you have a Mac, and the internet recovery fails. But think about a situation when your only Mac stops to boot, and you don’t have USB installer or TimeMachine backup! Downloading MacOS DMG file might save you. If you have a macOS DMG, you can create bootable USB disk from a Windows PC — use a software like TransMac for this purpose.

Clean installing or restoring a Mac offline with USB pen drive

As said earlier, you could use the macOS USB installer to do a clean install or restore it upon a boot failure. Just connect the USB disk and press the Option/Alt Key when you hear the boot sound. The Mac will then display all the startup disks available.

Pick the USB drive starting with the label “Install macOS” and follow on-screen instructions to complete the installation. If you need, use the Disk Utility to format the drive for doing a clean install.