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If you’re still using a Mac OS X the time will come when your computer won’t boot, or a problem may arise where you can’t take control of the device, and booting from an OS X installation media will be required.
This is why it’s recommended that you make a Mac OS X bootable USB when your Mac is in working conditions. However, if you find yourself on a scenario where your device (iMac, MacBook Pro, Air, Mac Pro or Mini) is not responding and you happen to have a Windows device, then you can still be able to make a USB bootable installation media for your Mac OS X to reinstall the operating system using the Recovery Assistant.
A broken Mac computer with Mac OS X. A trial copy of the TransMac software. One high quality USB flash drive with 16GB of storage. A copy of Apple’s macOS (DMG file). Now that you have all the necessary ingredients, you’re ready to make a Mac OS X bootable USB using the DMG file of the operating system with the steps below. Download Rufus Latest Version – Rufus is a free software to make bootable USB flash drive. The use of new technologies in the manufacturer of device components can result in the size of device components in smaller forms.
These instructions will also work for Windows users, who are running Mac OS X on a virtual machine and need to upgrade to the latest version. For instance, to OS X Yosemite.
Things to know before proceeding
Before you dive into this guide, you’ll need a few things:
- A broken Mac computer with Mac OS X.
- A trial copy of the TransMac software.
- One high quality USB flash drive with 16GB of storage.
- A copy of Apple’s macOS (DMG file).
Now that you have all the necessary ingredients, you’re ready to make a Mac OS X bootable USB using the DMG file of the operating system with the steps below.
How to create Mac OS X bootable USB installation media
Before you can use TransMac, you may first need to partition your USB flash drive with a GPT partition, as a normal MBR partition may not work. To do this, you’ll need to use the Diskpart command-line utility on Windows.
Setting up GPT partition
Use these steps to set up a USB drive with a GPT partition:
- Open Start on Windows 10.
- Search for Command Prompt, right-click the top result and select the Run as Administrator option.
- Type the following command to open Diskpart and press Enter:
- Type the following command to determine the USB flash drive and press Enter:
- Type the following command to select the storage and press Enter:Quick tip: The
select disk 1
command as an example, but you have to replace 1 with the number of the flash drive you want to use. - Type the following commands to delete everything from the USB thumb drive and press Enter:
- Type the following command to convert the drive into a GPT partition and press Enter:
- Type the following command to select the new partition and press Enter:
After you complete the steps, the USB flash drive from MBR to GPT format, you can use the steps below to create a bootable USB installation media to install Mac OS X.
Creating USB install media
Use these steps to create a bootable media to install Mac OS X:
- Download and install a copy of TransMac.Quick note: TransMac is a paid software, but it has a 15-day trial solution, that give us more than enough time to move the DMG files to the USB drive from Windows. (If you want to support the developer, you can purchase the full version.)
- Insert the USB drive that you’ll use to fix your installation of OS X. (Remember that all the data in the USB will be erased. Make sure you take off any important documents.)
- Right-click the TransMac software icon and Run as administrator. (You’ll be prompted to Enter Key or Run, because we’ll be using it once, click the Run option.)
- On the left pane, you’ll see all the Windows PC drives listed, right-click the USB drive that you’re intending to use to reinstall Apple’s OS X and select the Restore with Disk Image option.
- In the warning dialog box, click the Yes button.
- Use the Restore Disk Image to Drive dialog box to browse for the DMG file with the installation files for Mac OS X Yosemite in this case, and click the OK button to create a bootable USB of the operating system.Now, you’ll have to wait a long time. No kidding. It could take one or two hours to complete the process depending on your computer and other variables.
Once your bootable USB installation media is ready, remove it and insert it into your Mac, power it on, holding down the Option key, and select the USB you just created to reinstall Mac OS X.
If you’re having issues trying to create a bootable media, you can get a USB flash drive that comes with Mac OSX ready to install.
Update September 23, 2019: This guide has been revised to make sure it includes the latest changes.
Weekly Digest: Windows 10 previews, Surface Laptop 3, tech tipsHow to clone a Windows 10 installation to a new drive using ClonezillaAppleDifficulty level: IntermediateHow-ToOS XWindowsFor You
Installing Windows on a Mac should be a piece of cake with Bootcamp, but thatrarely is the case. In fact, I would personally say that Boot Camp Assistantis one of the worst apps that comes with OS X and unlike the rest, it doesn’twork seamlessly.
A few of its drawbacks:
- It only supports a drive with a single partition.
- It often throws very obscure error messages with limited detail.
- It re-downloads 1.6 GB Windows drivers every single time it runs. These areplaced under
/Library/Application Support/BootCamp/WindowsSupport.dmg
anddeleted and re-downloaded each time Boot Camp Assistant starts processing.
This post did take a lot of work to complie and I did bone my hard drive afew times while trying certain ideas, so please throw out a thanks if ithelped you out :)
Disclaimer: This guide below contains procedures which can potentiallydestroy your partitions and data. I accept no responsibility for such loss soplease proceed at your own risk.
Update (2016-07-20): I have updated this post with further improvementsrelating to downloading of Boot Camp drivers and ensuring that a Hybrid MBR isnot used (which would cause issues when installing Windows).
- An 8 GB or larger USB stick
- A copy of the Windows 10 ISO
- A valid Windows 10 license
- A downloaded copy of unetbootin
- Start Boot Camp Assistant
- Select Action / Download Windows Support Software
- Choose your Downloads directory, enter your password and then clickSave
This will be the only step that we will use Boot Camp Assistant for.
Formatting Your USB Stick
Attach your USB stick and start Disk Utility, select your USB drive in theleft panel under External, click Erase and set the options as follows(exactly) and click Erase:
Name: FAT32
Format: MS-DOS (FAT)
Scheme: Master Boot Record
Format: MS-DOS (FAT)
Scheme: Master Boot Record
Turning Your USB Stick into a Windows Installer
Open unetbootin, enter your password, set the options as follows andclick OK:
Diskimage: checked, set to ISO and browse to your Windows 10 ISO
Type: USB Drive
Drive: Your USB drive (you should only see one entry here)
Type: USB Drive
Drive: Your USB drive (you should only see one entry here)
If you see more than one drive listed, you may confirm which is your USB driveby opening the Terminal and typing:
You’ll see your USB drive in the output and it should look something like this:
Once you have kicked off unetbootin, grab a snack while the Windows ISO iscopied to the USB stick. This process takes around 15 minutes to complete.
Finishing Up
When this has completed, you may right click on the USB stick in Finder,select Rename “FAT32” and rename it as you like (I’ll call mine“WINDOWS 10”).
Finally, copy the WindowsSupport in your Downloads directory tothe Windows 10 USB stick so it’s easy to get to after our installation.
In Disk Utility, select your internal hard drive on the left panel, andclick on Partition.
Click the + button and create a new partition of your desired size for yourWindows installation and name it as you wish (I’ll call mine “BOOTCAMP”). Ensure that the Format is set to MS-DOS (FAT) and click on Apply.
Huge thanks to Rod’s post from the superuser post titledWindows detects GPT disk as MBR in EFI boot.
Once you add a FAT32 partition with either Boot Camp Assistant or Disk Utility,your disk is converted into a hybrid GPT / MBR disk which is actually notsupported by newer versions of Windows. In this step, we revert thisadditional change made by Disk Utility by switching back to a pure GPTpartition table.
- Dowload the latest version ofGPT fdiskby browsing to the version, then gdisk-binaries and clicking the filewith the *.pkg extension (e.g. gdisk-1.0.1.pkg).
- Install GPT fdisk by running the installer you downloaded
- Open a Terminal and check the state of your MBRIf your MBR partition is set to hybrid, please continue with step 4,otherwise if it is set to protective, you may skip the rest of thissection. Simply type q and hit return to exit GPT fdisk.
- Type p to view the existing partition table and verify you’re workingon the correct disk
- Type x to enter the expert menu
- Type n to create a fresh protective MBR
- Type w to save your changes and confirm the change when asked
- Type q to exit GPT fdisk
- Run GPT fdisk to show your disk layout:Your partition table should look something like this:
Disconnecting All Devices From USB Ports
This step is critical as I have had rather serious problems during Windowsinstallation when certain external drives are connected.
Unplug everything from your Mac except your keyboard (if wired) and yourbootable Windows USB stick (which we prepared earlier).
If your Mac contains multiple physical drives, you will need to disconnectall disks except the one which you intend to install Windows on or you mayencounter the following error:
Windows could not prepare the computer to boot into the next phase of installation. To install Windows, restart the installation.
Booting From the USB Stick
Ensure that the USB stick containing the Windows installer is inserted andthen restart your Mac while holding down the option (alt) key.
You should now be presented with a list of bootable drives. Select the USBdrive (usually titled “EFI Boot”) to begin installing Windows.
Correcting Your Windows Hard Disk Partition
When you are asked Where do you want to install Windows?, select theWindows partition created earlier (which I called “BOOTCAMP”) and clickDelete.
Next, select the chunk of Unallocated Space and click on New to createa proper Windows NTFS partition.
Note: OS X only supports creation of FAT filesystems, so this is why we needto re-create the partition ourselves during install.
Completing the Installation
Allow the installer to complete and boot into Windows.
Installing Boot Camp Support Software
Once Windows is up and running, install the Boot Camp Support software runningWindowsSupport/BootCamp/Setup.exe on your USB stick.
Note: The installer takes a little while to show up, so please be patient.
You may encounter a known issue whereby the Boot Camp Support Softwareinstaller locks up while installing Realtek audio.
If this occurs, you will need to open Task Manager and kill theRealtekSetup.exe process.
After the installer has completed, answer No when prompted to rebootand install the Realtek drivers manually by running%USERPROFILE%AppDataLocalTempRarSFX0BootCampDriversRealTekRealtekSetup.exe.If you can’t find this file, check any other directories starting withRARSFX under %USERPROFILE%AppDataLocalTemp.
Once complete, reboot Windows.
- The latest version of SharpKeys
- The flipflop-windows-sheel binary (see README for a download link)
Mapping Your Mac Keyboard
Install and run SharpKeys and then configure the following mappings tocorrect your Mac keyboard so that it behaves like a regular Windows keyboard:
Function: F13 -> Special: PrtSc
Special: Left Alt => Special: Left Windows
Special: Left Windows => Special: Left Alt
Special: Right Alt => Special: Right Windows
Special: Right Windows => Special: Right Alt
Special: Left Alt => Special: Left Windows
Special: Left Windows => Special: Left Alt
Special: Right Alt => Special: Right Windows
Special: Right Windows => Special: Right Alt
Note: for F13, you’ll need to select Press a key and click F13 on yourkeyboard.
Switching to Natural Scrolling
If you wish to flip scrolling direction to match that on OS X, runFlipWheel.exe and then click on Flip All.
Enabling Num Lock on Boot
Paste the following into a file named Enable NumLock on Boot.reg thenimport this into the registry to enable NumLock when Windows boots up(it doesn’t by default).
Completing Configuration
That’s it, give your machine one last reboot and you’ll have a fully workingWindows 10 installation.
Note: I have found Apple’s Magic Mouse to be extremely unreliable usingthe Boot Camp drivers from Apple. As such, I recommend purchasing a Logitech(or similar) mouse for use in Windows. I have no trouble plugging thewireless receiver for my Logitech mouse into one of the USB ports of my wiredApple Keyboard and it’s so tiny that you can’t see it at all.
Removing the Windows Partitions
If you decide to remove Windows, you may find that Disk Utility doesn’t allowyou to delete the two partitions that have been created by the Windowsinstaller.
This happens due to the fact that the first small partition created is of atype called Microsoft Reserved which OS X’s Disk Utility doesn’t support.
The safest way to delete these partitions is through the Windows installer. Sosimply boot from your USB stick as we did before and when you reach theWhere do you want to install Windows? question, you may delete your“BOOTCAMP” partition and the small 16 MB partition of type MSR (Reserved)just above the BOOTCAMP partition.
Once done, simply quit the installer by clicking the X in the top right cornerof each Window and reboot back into OS X.
Removing the Boot Entry
Even though we have removed the Windows partition, a boot entry will still bepresent when holding down option (alt) during boot.
You may remove these items by running the following in your Terminal: