As you may know, you can reinstall macOS on your computer via the internet recovery. But did you know that you can create a bootable USB drive to install macOS from? This will let you boot your Mac from a different source if it won’t work normally, and makes installs on multiple machines easy.
UNetbootin is a free, open source utility that allows you to create bootable USB drives on Windows, Linux, and Mac OS X. If you’ve downloaded Windows 10 ISO image, here is how you can create a bootable Windows installer USB on Mac using UNetbootin. Plug a USB drive into your Mac and open Disk Utility.
Let’s see how to do this.
Choosing a USB Flash Drive for Installing macOS
USB flash drives are cheaper than ever, so you won’t have to spend much for this task. However, make sure to buy a name-brand flash drive (like SanDisk, Kingston, or PNY) from a reputable store. Stay away from super-cheap drives with suspiciously high storage on sites like eBay.
These drives have their firmware hacked to report a false size to your operating system. Not only will the transfer speeds be painfully slow, but using them may also result in loss of data or even a damaged USB port.
Also, check to see what ports you have on your Mac. The 12″ MacBook has a single USB-C port, while MacBook Pro models from 2016 and later feature USB-C ports exclusively. Fortunately, there are USB-C drives available, or you can use a USB-C to USB-A adapter.
It’s best to go with a USB 3.0 drive, with a minimum size of 16GB. The Samsung BAR Plus is good overall value for the money; we’ve highlighted the fastest USB 3.0 drives you can buy for more options.
Formatting Your USB Flash Drive
You can only create a bootable installer for macOS on a Mac. If you’re using a flash drive that already has data on it, make sure to back up any important files as you’re going to erase everything in a moment.
Open Finder. Navigate to Applications > Utilities, and open up Disk Utility. You should see your flash drive under the External section in the left pane. After selecting it, click on the Erase button along the top.
Choose a friendly name (which you’ll use later), and make sure to choose Mac OS Extended (Journaled) for the format. Finally, click Erase and you’re done with this step.
Downloading the macOS Installer
To download the macOS installer, open the App Store and search for your version of macOS. Click on the Download button if you’re on High Sierra or earlier.
macOS Mojave is slightly different, as it opens up your System Preferences to download the installer. This is because one of the changes in Mojave is a new way of installing updates.
In either case, once the installer opens, quit it without continuing the installation.
Creating a Bootable USB Using Terminal
Terminal is the easiest way to create your bootable USB drive. Just replace the MyVolume portion of the command with the name you gave your drive in the Disk Utility step above.
Take note that the commands differ slightly for creating Mojave and High Sierra installers on older versions of macOS.
Mojave installer on Mojave or High Sierra:
Mojave installer on Sierra or earlier:
High Sierra installer on High Sierra:
High Sierra installer on Sierra or earlier:
Sierra:
El Capitan:
Copy and paste the command you need above into your Terminal window and press the Return key. After entering your password, confirm you want to erase the USB drive by typing Y followed by Return.
Terminal will now erase and create your bootable USB drive, ready for you to boot from.
Creating a Bootable USB Using DiskMaker X
If you’re not a fan of using Terminal, you can try a third-party app designed specifically for creating a bootable macOS USB drive. After downloading your macOS version of choice as detailed above, you can download and install DiskMaker X.
Due to its updated security, macOS Mojave has some additional steps required if you’d like to use DiskMaker X. The developers recommend reversing these changes after you’ve made your USB drive if you’re not planning on using the app in the future.
Navigate to System Preferences > Security & Privacy > Privacy > Accessibility. To make changes, click the lock icon at the bottom and enter your credentials.
Then click on the Plus button, navigate to the Applications folder, select DiskMaker X, and click open. DiskMaker X should now appear on the list.
As soon as you launch DiskMaker X, it will prompt you to confirm the macOS installer you’ve downloaded.
The next prompt shows one of the advantages of DiskMaker X in that you can create a multi-installation disk. This means that you can create a few partitions on your USB drive and have a different macOS installer on each partition.
If you would rather create a single install disk, select Erase All Disk. Lastly, confirm that you’d like to erase everything on the USB drive.
DiskMaker will continue to create your disk in the background and update you on its progress. After a few minutes, DiskMaker X will notify you that your boot disk is ready and give you some instructions on how to use it.
Booting Your Mac From a USB Drive
Now if you find yourself in a sticky situation where your Mac isn’t booting, or you want to do a fresh install of macOS, you have a solution. You can boot from your USB drive and not have to download the macOS installer again. This will come in handy for fixing the “macOS could not be installed” error How to Fix the macOS Could Not Be Installed on Your Computer ErrorSeeing the 'macOS could not be installed on your computer' error when you try to update? Here's how to fix this macOS error. Read More .
Simply plug your created USB drive into an open USB port on your Mac. Power on the system, or restart it if it’s already on. Immediately press and hold the Option (Alt) key on your keyboard when it starts booting.
You should now see an option to select your USB drive as a startup disk. After selecting it, your system will boot off your USB drive and you’ll be taken to the macOS Utilities screen.
Some wireless keyboards may not work at this point. If you’re having difficulty, plug in a wired keyboard instead. If you don’t see your USB drive as one of the startup options, try a different USB port.
Using Your Bootable macOS USB
From the macOS Utilities screen, you can perform a fresh install of macOS, restore from a Time Machine backup, or access tools like Disk Utility. You can also use your USB drive to upgrade macOS to the latest version. If you need to troubleshoot your Mac without a network connection, this USB drive could be a lifesaver.
Did you know you could also install multiple operating systems on a USB stick How to Install Multiple Bootable Operating Systems on a USB StickWant to install and/or run multiple operating systems from a single bootable USB stick? You can with these tools. Read More ? We show you how:
Image Credit: karandaev/Depositphotos
Once you install Yosemite, the file will automatically erase itself, so it's important to make a bootable drive first. If you want to install first and then make a bootable drive, make a copy of the installer app in another location so you can access it later.
Worst case scenario is downloading the large file again from the Mac App Store, but then why make a bootable drive? The Easiest Way: Use DiskMaker XBy far the easiest way to create a bootable drive is to use the DiskMaker X application, which automates the entire process in the next method. To start out, download the newest version of DiskMaker X from. Currently, that's the. (Update: the public Yosemite version is out now, and you can download it from, or.)Once download, open it up and select 'Yosemite Beta' or 'Yosemite 10.10' (depending on the version you're using) to start the process. Then just follow the rest of the prompts to start the disk-making process.
It could take anywhere from 15 minutes to to 45 minutes to finish, depending on your USB flash drive. If it's more toward the latter, you might get a ' error, but it should still work, (it worked for me). The Less Easy Way: Format & Use TerminalIf you're more comfortable with Terminal commands, this is the method for you. Just make sure your USB drive is already formatted correctly before proceeding. To see how to correctly format your USB drive, please see Step #1 below in the 'The Hardest Way' section.With your USB drive ready to go, open up Terminal and type (or copy/paste) the following command. sudo /Applications/Install OS X Yosemite.app/Contents/Resources/createinstallmedia -volume /Volumes/Yosemite -applicationpath /Applications/Install OS X Yosemite.app -nointeractionNote that you should replace the 'Yosemite' in 'Volumes/Yosemite' with whatever you named your USB drive.This should all be one line. After you get it in there, just hit the Enter key.
Type in your admin password to continue and the Enter again. (You won't visibly see your password typing, but it's happening—believe me.)Now just wait. This could be fairly quickly or very long, depending on your system and USB drive. The Hardest Way: Do Everything ManuallyIf you don't want to use DiskMaker X or Terminal commands, this is another option for you.
It's a lot more complicated, but gets the job done. Step 1: Reformat Your USB DriveFirst, make sure you have a USB flash drive that's at least 8 GBs in size, then mount it. Open up Disk Utility and do the following. Select the USB drive (not the partition). Go to the Partition tab. Change the 'Partition Layout' to 1 Partition. Rename it Yosemite (or whatever you want).
Select Mac OS Extended (Journaled) as the 'Format'. Click the Options. After your Finder reloads, the hidden files you once saw before should now be gone. Go ahead and close all of your windows, exit Terminal and Disk Utility, and eject your mounted disks to clean up your mess. Installing Yosemite on Your ComputerNow, it's time to test out your new drive. Restart your computer while holding the Option (Alt) key on your keyboard. Wait until the Startup Manager pops up, then select your new OS X Base System volume (or whatever your bootable drive is called).
Alternatively, you can just hold down the C button while starting up to boot directly into the USB drive. Troubleshooting TipsIf the installation of Yosemite freezes, it's probably because your USB drive is corrupted in some way. This happened to me on the first couple tries, where it would freeze at 5 minutes left. The third USB stick I used was successful, and it took less than 15 minutes for Yosemite to boot up.If you're getting an Undefined error: 0 warning when trying to install, this more than likely means that you forgot to perform Step 6 above, so make sure to copy over those two BaseSystem files.If you got the 'AppleEvent timed out' error using DiskMaker X, more than likely it'll still work. Just eject the new drive and use it.
If it doesn't work, try one of the other methods out to start over.If you're not sure if you're going to like Yosemite over Mavericks, I would suggest and installing Yosemite there, that way if anything goes wrong, your Mavericks installation will still be untouched. Get Gadget Hacks on,. Sign up for. Subscribe toCover image via. Talk about the long way of achieving this!Very thorough tutorial but unnecessary.Assuming you have downloaded the BETA version of Yosemite, open up the installer from the Application folder, but do not proceed with the installer, just leave it open.Then follow step 1 as per this tutorial. Once your USB drive has been formatted add copy and paste the following into Terminal:sudo /Applications/Install OS X Yosemite Beta.app/Contents/Resources/createinstallmedia -volume /Volumes/UNTITLED -applicationpath /Applications/Install OS X Yosemite Beta.app -nointeractionWhere UNTITLED is the name of your formatted volums/USB drive e.g. Yosemite.Wait (a while, no really, you'll be waiting quite some time if you're not using USB 3.0 or Thunderbolt) and then you'll be ready to boot and clean install Yosemite BETA from your USB drive.Carry on from Step 8.No need for lengthy process of hiding.unhiding files.folders nor is there a need to drag and drop files/folders.Don't forget to backup!
Hi!Great tutorial and thanks for your hard work and for your generosity!I did the usb installation, i installed on the hard drive and when i tried to boot from hdd the boot process stops and the computer reboots. I used the flags: -s -x -f -v kext-dev-mode=1 KernelCache=No.I have a emachines E725, dual core T4400, 3 GB Ram, 320GB HDD, integrated graphic card Intel GM45, i don't know the type of the motherboard of this machines with windows 7, xubuntu 14.04 and mavericks 10.9.5 on it.Please help me! I NEED HELP!! I know I'm a few years late but I JUST came into possession of a 2007 macbook (A1181) and I'm upgrading the RAM (to 4GB) and hard drive (to 500 GB). I was hoping to make myself a bootable installer of Yosemite but I cannot manage to find anywhere to download it. That is the only thing hanging up my adventure.
I'd be open to any other macOS as long as it can run the newest iTunes. I'm wary of going too high since this laptop is so old and I'm pretty new to doing my own upgrades. THANKS!!:) Reply.