Install

UNetbootin can create a bootable Live USB drive, or it can make a 'frugal install' on your local hard disk if you don't have a USB drive. It can load distributions by automatically downloading their ISO image (CD image) files, or by using existing ISO files, floppy/hard disk images, or kernel/initrd files, for installing other distributions. Step 3: Create a bootable USB disk. Next we need to turn out USB drive into a bootable USB disk so that we can use it to install a new copy of macOS on our Mac after we have reformatted it (that. Grab a USB stick with 16GB capacity or an external hard drive or SSD and plug it in to your Mac. Launch Disk Utilities and Erase the Drive or USB stick, formatting it as Mac OS Extended (Journaled) and selecting GUID partition map if a selection is available. The easiest way to create a bootable installer is to use DiskMaker X.

What’s needed for a clean install on a Mac

  1. A backup of the disk before it’s erased. Two options are to use Duplicate (a free utility which can copy and paste an entire bootable volume), or Mac Backup Guru (a paid, fully featured backup utility with unique incremental backups capability) for that. Here is a detailed guide for the process.
  2. A Mac operating system installer. MacOS Big Sur can be downloaded by clicking here.

If you need to recover deleted files take a look at Mac Data Recovery Guru on our sister-site dedicated to data recovery.

Paypal / credit card donations: click here
Bitcoin donations: 1MbwUFSbQvMrd826DTpup7PpTTNrrJjaJ8

Total downloads: 1,678,418
Total donated: $33.99

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.

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

Usb

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:

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.

Bootable Macos Catalina Usb Install Drive Cable

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.

How To Make A Bootable Macos Catalina Usb Install Drive

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.

Usb

Part 4: Boot Mac from macOS USB Drive for Installation

Bootable Macos Catalina Usb Install Drive

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.

Usb

Conclusion:

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.