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.
- Bootable USB Installers for OS X Mavericks, Yosemite, El Capitan, and Sierra First, review this introductory article: Create a bootable installer for macOS. Second, see this How To outline for creating a bootable El Capitan installer. DMG file is a compressed file format being used widely on Mac computer.
- Mac OS X El Capitan 10.11. After that TransMac will create bootable Mac OS USB within few minutes.
- On the license page, click Continue and select Agree to continue. Now choose the USB Thumb drive you want to create bootable and click Continue. At this point, select the OS installation ( El Capitan) and click Continue. Now select the bootloader configuration UEFI Boot Mode then click Continue.
Part 1: Download macOS or Mac OS X DMG File
The El Capitan installer file came down to my Applications folder without problem, but multiple repeat attempts to create a bootable USB (16gb) drive using Diskmaker X 5 has failed. The program appears to go through all the steps, but finally the USB drive is never findable as a bootable drive. Created a bootable USB with El Capitan installer. Booted from it, erased my MBP (mid 2009), clean install from USB installer. Decided to use migration assistant, most apps not working plus all the clutter from pre clean install. Decided to do another clean install but MBP won't boot from USB and uses the recovery version instead.
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: Easily Create a 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:
Updates (Dec 8, 2020): The latest version of UUByte DMG Editor is able to format the USB automatically.
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.
Create Bootable Usb Mac Os El Capitan
Part 3: Format USB Drive to GPT If Failed
If the USB drive created in above step was not seen as a bootable device on your Mac, then you need to take an addtional step before burning. That's formatting the USB to GPT.
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 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.
Troubleshooting
Flashing Error: You might receive a flashing error message at the end of burning process. Please don'y worry and ignore this error. The USB becomes a bootable disk and you can use it to install macOS even this error pops up.
Bootable Os X El Capitan
About Official EI Capitan DMG: There has a serious bug in the official release of OS X El Capitan, which contains .pkg installer only. The burning process will fail for sure. Please use this modified EI Capitan DMG file instead, which was approved a good option.
Registration Failed: Please make sure the computer is connected to Internet and no proxy or VPB is running during registration. If the problem still exists, please send an email to support team asking for a new code.
Bootable Usb Drive Creator Tool
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.