Create Bootable Usb From Dmg In Mac

If your Mac suddenly refuses to boot up properly, you might need bootable macOS install USB 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.

Part 2: Format USB Drive to GPT

Jan 19, 2018 Use 'createinstallmedia' Command in Terminal. Step 1: Download macOS or OS X. The first thing to do is to download the Mac operating system that you need. To install the latest Mac OS, for. Step 2 Get A USB Drive with Sufficient Storage. You should have a USB drive with at least 8 GB of storage. Choose An 8GB USB thumb drive Select the USB volume name, then select Choose this disk Click on Erease to format the USB and create the disk Click Continue, you then are asked for admin and password.

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

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

Create

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

Step 2: Insert your formatted USB drive, and you will be able to see it in the TransMac software on the left panel.

Step 3: Right-click the USB and select Restore with Disk Image in the contextual menu. Click Yes in the warning popup.

Step 4: You will see a window that says Restore Disk Image to Drive. Here, select your DMG file in the dropdown menu and click OK.

Depending on the system configuration, this can take anywhere from a few minutes to a couple of hours. Once the progress bar is at 100%, a bootable USB is ready.

Part 4: Boot macOS Install USB on Mac

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:

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 TransMac software won't be bootable, which means you can't install macOS using it, and you may need to do the whole thing over again.

To create a bootable USB drive from a DMG file on Windows, you will need to have the right utility. That's because DMG is not native on Windows. It is the Mac equivalent of an ISO file that has been in use since Apple transitioned from the IMG format with Mac OS X. A DMG file, like ISO, can be used to install macOS operating system or Mac apps. If the Mac computer was broken or crashed and couln't get into the system, but you only have access to a Windows PC, there's still a way to make a bootable macOS install USB on Windows.

This article looks at three applications that you can use to create a bootable USB drive from a DMG file in Windows. All of them have their advantages and disadvantages, which we have highlighted. You can make the best choice for you based on the information provided below. They are in no particular order of preference.

TransMac - Make DMG File Bootable USB on Windows

This is a fairly robust application for creating bootable USB on Windows from a DMG file. However, there's a preparatory step to be executed before you can create the bootable USB drive. The typical disk partition used is MBR, but you will need to do a partition with GPT for this to work. You can do so by executing the diskpart command in Windows CMD. Alternatively, you can do it from within TransMac, as shown in the instructions shown below the next paragraph.

Once this is done, you can download TransMac and use the two-week free trial period to get the job done free of cost. You can always upgrade if you like the utility and want to keep using it after the trial period has ended. Once you download and install the application, insert your formatted USB drive and follow the instructions below:

Step 1: If you haven't formatted the USB, right-click on your USB drive in the left panel and select Format Disk for Mac from the contextual menu.

Step 2: Right-click again on the drive in the left panel and this time select Restore with Disk Image.

Step 3 : Select the DMG file and click on Open. Once the process is complete, you can eject the drive and use it on a Mac. To boot from this media, hold down the Option key and fire up your Mac.

Convert DMG to ISO and Create macOS Boot USB from Windows

Since ISO is a better format for Windows, you can also convert the DMG to the ISO format and then use the ISO disk image to create the bootable USB. Please note that you can't boot your Mac from bootable USB made from an ISO file, which means you'll have to convert it back to DMG prior to that. Still, it's an effective way to create bootable media for a Mac computer. Here's how it works:

Create Bootable Usb From Dmg In Mac Download

Step 1: Once you have the macOS install DMG file on a Windows PC, click on Windows + R to open the run dialog box, and type in CMD, then hit Enter. When the Command Prompt opens up, use the following command to convert the file to ISO:
hdiutil convert /path/sourceimagefile.dmg -format UDTO -o /path/targetmage.iso

Step 2: Download and install UUByte ISO Editor on your PC, insert the USB drive and launch the application.

Step 3: Click Burn button on the main screen and point to the converted ISO file. The drive will be automatically detected and click on Burn icon to burn the ISO to the USB drive.

Once the ISO is burned to the file, you can insert it into a Mac and convert it back into the DMG format. Since you're converting the file twice, there's a chance that the file could get corrupted in the process. If that happens repeatedly, then try this next method.

PowerISO: Make Bootable Mac Install USB on Windows 10/8/7

This Windows utility allows you do create bootable USB from DMG on a PC. You can also edit the DMG or extract the contents, and there's also an option to copy it to a disk. For this particular exercise, we'll show you how to use PowerISO to create a bootable USB drive on Windows without having to convert the disk image into another format like ISO.

Step 1: Download and install the application on your PC.

Step 2: Insert your USB drive and launch PowerISO.

Step 3: In the Tools menu, select 'Create Bootable USB Driveā€¦ '. You will need to give admin privileges to the software. Alternatively, you can run the program as admin when you launch it.

Step 4: Select the USB drive in the section called Destination USB Drive.

Step 5: Leave all other default as they are and click on 'Start' to burn DMG to the USB drive.

You should be able to see the progress, and a new popup will appear when the bootable media is ready. You can now eject the media and use it to run the DMG on a Mac computer.

Conclusion:

Make Boot Usb From Dmg Mac

All of these methods are workable, so select the right one for you based on your level of knowledge and your preference.