- Nov 21, 2010 Question: Q: How to restore from a dmg file? My MAC was working fine and at that point from Disk Utility, selecting the main disk, I clicked on 'New Image' and saved the entire disk as a backup. It resulted in a 135Gb dmg file.
- Is it possible to restore the.dmg to the external hard drive where the.dmg file resides? If not, how do I restore these files? If not, how do I restore these files? I have some very important files on there so I don't want to go testing something and then accidentally wiping that backup.
- Jul 08, 2011 Solution: Re-dowload OS X Lion, Open Disk Utility, locate InstallESD.dmg file from SharedSupport folder and double click it (Automatically the InstallESD.dmg and Mac OS X Install ESD is going to mount in the Disk Utility application on the left side), Drag the Mac OS X Install ESD file to the Source and Drag your usb partition (if you have more than one partition on your usb) to the Destination.
Jesus Vigo goes over the steps to create a bootable USB to install OS X 10.7-10.8 and OS X 10.5-10.6, as well as how to put multiple versions on the same USB. Unmount the dmg file named “Install macOS Sierra.dmg” (if it is mounted:) Go to the top menu of “Disk Utility” window and select “images” and then “Scan image for restore” Go to the “Install macOS Sierra.dmg” and click open.
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:
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 Drive… '. 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:
All of these methods are workable, so select the right one for you based on your level of knowledge and your preference.
Reinstall from macOS Recovery
macOS Recovery makes it easy to reinstall the Mac operating system, even if you need to erase your startup disk first. All you need is a connection to the Internet. If a wireless network is available, you can choose it from the Wi-Fi menu in the menu bar. This menu is also available in macOS Recovery.
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Release the keys when you see an Apple logo, spinning globe, or other startup screen.
Command (⌘)-R
Reinstall the latest macOS that was installed on your Mac (recommended).
Option-⌘-R
Upgrade to the latest macOS that is compatible with your Mac.
Shift-Option-⌘-R
Reinstall the macOS that came with your Mac, or the closest version still available.
You might be prompted to enter a password, such as a firmware password or the password of a user who is an administrator of this Mac. Enter the requested password to continue.
When you see the utilities window, you have started up from macOS Recovery.
2. Decide whether to erase (format) your disk
You probably don't need to erase, unless you're selling, trading in, or giving away your Mac, or you have an issue that requires you to erase. If you need to erase before installing macOS, select Disk Utility from the Utilities window, then click Continue. Learn more about when and how to erase.
3. Install macOS
When you're ready to reinstall macOS, choose Reinstall macOS from the Utilities window. Then click Continue and follow the onscreen instructions. You will be asked to choose a disk on which to install.
- If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
- If the installer doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.
- If the installer is for a different version of macOS than you expected, learn about macOS Recovery exceptions.
Please allow installation to complete without putting your Mac to sleep or closing its lid. During installation, your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.
If your Mac restarts to a setup assistant, but you're selling it, trading it in, or giving it away, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.
macOS Recovery exceptions
Write Dmg To Usb
The version of macOS offered by macOS Recovery might differ in certain circumstances:
- If macOS Sierra 10.12.4 or later has never been installed on this Mac, Option-Command-R installs the macOS that came with your Mac, or the closest version still available. And Shift-Option-Command-R isn't available.
- If you erased your entire disk instead of just the startup volume on that disk, macOS Recovery might offer only the macOS that came with your Mac, or the closest version still available. You can upgrade to a later version afterward.
- If your Mac has the Apple T2 Security Chip and you never installed a macOS update, Option-Command-R installs the latest macOS that was installed on your Mac.
- If you just had your Mac logic board replaced during a repair, macOS Recovery might offer only the latest macOS that is compatible with your Mac.
If you can't get macOS Recovery to offer the installer you want, you might be able to use one of the other ways to install macOS.
Other ways to install macOS
Mac Restore Dmg To Usb Converter
- You can also install macOS from the App Store or Software Update preferences. If you can't install macOS Catalina, you might be able to install an earlier macOS, such as macOS Mojave, High Sierra, Sierra, El Capitan, or Yosemite.
- Or create a bootable installer disk, then use that disk to install macOS on your Mac or another Mac.