Once downloaded move the Install Mac OS X El Capitan.app to your Mac, and then create a new bootable USB, Create a bootable installer for macOS - Apple Support More Less Feb 28, 2017 11:59 PM.
- As has been the case for the last few releases of OS X, the easiest method to make a USB install drive is with the free program, Diskmaker X. It’s been updated today to support El Capitan.
- If you wanna create bootable USB flash drive for Mac OS X El Capitan on Windows PC. You need a TransMac Software. That’s not a problem if you use a computer that supports legacy or UEFI. Just you need TransMac and El Capitan dmg file. Siddharth choubisa September 20, 2016 at 3:43 PM.
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: 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.
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.
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.
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.
Summary
How to make a bootable USB drive on Linux Mint (19.3) to allow you to install Mac OS X El Capitan on a MacBook with broken or corrupted recovery mode.
Background
I was recently given a 2011 MacBook Pro that had been “well-loved” and was therefore a mess of missing applications, ghost files and generally slow-as-hell. Since there wasn’t much worth saving I wiped it and initiated recovery mode in order to re-install OS X (El Capitan).
Having recently fixed a busted MacBook Air I had learned a bit about Recovery Mode (hold Command+R whilst pushing the Power button and release a few seconds after the machine wakes up). I tried that with this machine, and upon hitting “Reinstall MacOS X” was greeted with a prompt telling me it would take -2,148,456,222 days and 8 hours (an uncaught buffer overflow, me thinks). After about 30 seconds, a window pops up saying “Can’t download the additional components needed to install Mac OS X” and the installation gives up. The detailed error log says “Chunk validation failed, retrying” about 1000 times and eventually gives up altogether.
Further investigation suggests this may be something to do with security certificates having expired and hence the machine not being able to download the necessary files from Apple’s servers, but it seems the error can appear for all sorts of reasons. I also tried Internet Recovery (Command+Option+R) but that gave exactly the same error (and would also only have installed OS X Mountain Lion).
I then turned to attempting to make a bootable USB stick of OS X El Capitan from an image downloaded from Apple. I use Linux Mint on my main laptop and that was all I had available. Apple seem to assume everybody has a spare MacBook from which to create a bootable USB so they provide absolutely no documentation to help with this. I also couldn’t find a single guide online that worked from start to finish, so here I summarise what needs to be done.
Steps
As usual, this is all at your own risk 🙂
First you need to go to Apple’s OS Download Page and (step 4) get ahold of “InstallMacOSX.dmg” for El-Capitan. It’s a 6GB file so it might take a ‘lil while. You will also need to find a USB drive with at least 8GB capacity, and make sure it’s blank. The format doesn’t matter, because this procedure will format it correctly.
(In total you will need to use about 15-18GB of disk space by the time you’ve done all the extracting necessary, which shouldn’t be a problem for most computers but it was a challenge for my laptop with it’s 128GB SSD and dual boot Windows/Linux!)
Then you need to get a program called ‘dmg2img’
You can then extract the DMG
Download El Capitan To Usb
Now double click the .img file to mount it. In there is a InstallMaxOSX.pkg file. This requires a utility called “xar” to extract, which can be installed with these instructions (from https://www.oueta.com/linux/extract-pkg-and-mpkg-files-with-xar-on-linux/)
Then build and install with
Now you can extract the .pkg file. It will extract to the current working directory
Now, within the extracted files you will find something called InstallESD.dmg. This actually contains all the interesting boot files, but it isn’t a pristine image, so we can’t just burn it to a USB. Thankfully, a script exists to convert this DMG to a bootable usb, and it’s available here. It takes the DMG and writes everything directly to the USB in the right place.
ONE CAVEAT: When I ran this script on my InstallESD.dmg, it crashed because it didn’t recognise the checksum. I think this is because Apple updates the dmg’s anytime there is a security update for El Capitan so the checksum list isn’t updated. All I did was delete the checksum check from the script above. Essentially, just open the script and delete this section
Once I had done this, I ran the script with my USB connected (/dev/sdb for me, but CHECK YOURSELF with fdisk or similar) and after quite a while it finished copying.
El Capitan Mac Os Bootable Usb Download
I plugged the USB into the MacBook, and opened the startup menu by holding down Option whilst pushing the power button. This gave me the choice of booting from EFI, or choosing a WiFi network. Click on the EFI, and then follow the prompts to install OS X from the USB drive!
Mac Create Bootable Usb From Iso
When you’re done, you may need to use Parted or a similar utility to re-format your USB as a normal drive again.