Catalina Bootable Disk

Posted By admin  On 15.09.21


Catalina bootable-disk. Improve this question. Follow asked Nov 1 '19 at 19:26. Martin Macak Martin Macak. 142 4 4 bronze badges. Why not just use Internet. Insert your USB flash drive (4Gb + preferable) into your system. Warning: All data on the USB flash drive will be lost, make sure you save any data before proceeding. Navigate to the Command Prompt. Select Start & type CMD in the search field, right click on CMD.exe and select Run as administrator.

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.

Catalina Boot Disk Creator

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.

Catalina

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

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.


Apple hasn’t shipped operating systems on physical media in a full decade, but there are still good reasons to want a reliable old USB stick for macOS Catalina. Luckily, it's not hard to make one—either with a handy graphical user interface or some light Terminal use. Here's what you need to get started:

  • A Mac that you have administrator access to. We've created a USB stick from both Mojave and Catalina, but your experience with other versions may vary.
  • A 16GB or larger USB flash drive or a 16GB or larger partition on some other kind of external drive. A USB 3.0 drive will make things significantly faster, but an older USB 2.0 drive will work in a pinch; 8GB drives worked for Mojave and older versions of macOS, but the Catalina installer is just a little too large to fit.
  • The macOS 10.15 Catalina installer from the Mac App Store (in High Sierra or older macOS versions) or the Software Update preference pane in Mojave. The installer will delete itself when you install the operating system, but it can be re-downloaded if necessary.
  • If you want a GUI, take a look at Ben Slaney's Install Disk Creator from MacDaddy. There are other apps out there that do this, but this one is quick and simple.

If you want to use this USB installer with newer Macs as they are released, you'll want to periodically re-download new Catalina installers and make new install drives. Apple rolls support for newer hardware into new macOS point releases as they come out, so this will help keep your install drive as universal and versatile as possible.

Catalina Bootable Disk

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There's also one new consideration for newer Macs with Apple's T2 controller chip—as of this writing, that list includes the iMac Pro, the 2018 Mac Mini, the 2018 MacBook Air, and 2018 and 2019 MacBook Pros, though Apple keeps an updated list here. Among this chip's many security features is one that disallows booting from external drives by default. To re-enable this feature, hold down Command-R while your Mac reboots to go into Recovery Mode and use the Startup Security Utility to 'allow booting from external media.' If you're trying to install an older version of macOS, you may also need to go from Full Security to Medium Security to enable booting, but if you're just trying to install the current version of macOS, the Full Security option should be just fine. And if you're just doing an upgrade install rather than a clean install, you can run the Catalina installer from the USB drive from within your current installation of macOS, no advanced tweaking required.

The easy way

Once you've obtained all of the necessary materials, connect the USB drive to your Mac and launch the Install Disk Creator. This app is basically just a GUI wrapper for the terminal command, so it should be possible to make install disks for versions of macOS going all the way back to Lion. In any case, it will work just fine for our purposes.

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Install Disk Creator will automatically detect macOS installers on your drive and suggest one for you, displaying its icon along with its path. You can navigate to a different installer if you want, and you can also pick from all the storage devices and volumes currently connected to your Mac through the drop-down menu at the top of the window. Once you're ready to go, click 'Create Installer' and wait. A progress bar across the bottom of the app will tell you how far you have to go, and a pop-up notification will let you know when the process is done. This should only take a few minutes on a USB 3.0 flash drive in a modern Mac, though using USB 2.0 will slow things down.

The only slightly less-easy way

The Install Disk Creator is just a wrapper for the terminal command to create macOS install disks, so if you’re comfortable formatting your USB drive yourself and opening a Terminal window, it’s almost as easy to do it this way. Assuming that you have the macOS Catalina installer in your Applications folder and you have a Mac OS Extended (Journaled)-formatted USB drive (which is to say, HFS+ and notAPFS) named 'Untitled' mounted on the system, you can create a Catalina install drive using the following command.

sudo /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

The command will erase the disk and copy the install files over. Give it some time, and your volume will soon be loaded up with not just the macOS installer but also an external recovery partition that may come in handy if your hard drive dies and you're away from an Internet connection. If you would like to create an install drive for a macOS version other than Catalina, just tweak the paths above to refer to Mojave or High Sierra instead.

Whichever method you use, you should be able to boot from your new USB drive either by changing the default Startup Disk in System Preferences or by holding down the Option key at boot and selecting the drive. Once booted, you'll be able to install or upgrade Catalina as you normally would. You can also use Safari, Disk Utility, or Time Machine from the recovery partition to restore backups or troubleshoot.