How to create a bootable macOS High Sierra installer drive Put the macOS High Sierra installer on an external USB thumb drive or hard drive and use it to install the operating system on a Mac. UniBeast is a tool by MacMan and tonymacx86 to create a bootable USB drive from any Mac App Store purchased copy of OS X. This is an all-in-one bootable USB drive can also be used as a rescue boot drive for system recovery. However, without this tool, there is TransMac that you can use them on your Windows operating system. This tutorial is for Mac OS that is based on Mac OS versions and successfully working on Windows 10. The Mac OS image is required in order to proceeding further steps (i.e. Mac OS DMG / ISO files) and a USB Pen drive with minimum 8gb size is required.

Although Macs are reliable machines, they are not exempt from hiccups. All you need to do is carry around a single USB flash drive to be ready for situations the require you to diagnose, repair, or experiment with Mac OS X.

One of the maintenance tools every Mac user should have available in case of emergency is a bootable copy of Mac OS X on a removable device. A clean installation of the operating system can help pinpoint problems and will come to the rescue in a bind. And since most Mac owners use a MacBook of some kind nowadays, portability is a valuable thing. That means carrying around a bulky external hard drive with cables is not always ideal. It turns out a tiny USB flash drive serves as a great alternative.

Not sure when having OS X loaded on a flash drive would come in handy? Here are just a few examples:

• Your Mac isn’t starting correctly and you’re not sure if the internal hard drive is failing or if another piece of hardware is to blame.
• The file system on your startup disk has become corrupt and needs to be repaired.
• A software problem is plaguing your Mac and you’d like to see if you can replicate it in an isolated environment.
• Your Mac’s hard drive is completely dead and you’d like to use your computer for basic tasks like email and web browsing while you wait for your new drive to arrive.

Now that you’re convinced, let’s figure out how to do this. First you’ll need an Intel-based Mac from the past few years. Second, at least a 16GB USB flash drive, such as this SanDisk Cruzer Micro for about $30 at Amazon. Keep in mind 10.6 Snow Leopard was used to demonstrate this tutorial, so I’m not sure how much space 10.5, 10.4, and earlier require. While they should be fine, squeeze those versions of Mac OS X on a 16GB drive at your own risk. And the third thing you’ll need to get the job done is your OS X installation DVD.

1. To start things off, connect the USB flash drive to your Mac. Make sure there’s no valuable data on there because it will be permanently wiped out in a couple minutes.
2. Open Disk Utility (Applications > Utilities) and click on your flash drive in the list on the left.
3. Go to the Partition tab and select “1 Partition” from the Volume Scheme menu. Enter a name for the volume (I called mine “OS X USB”), select “Mac OS Extended (Journaled)” as the Format, and make sure the size is somewhere around 15-16GB.
4. Click on the Options button towards the bottom and choose “GUID Partition Table” from the popup window. Click OK.
5. Now that all of the settings have been chosen, click the Apply button and then Partition. Disk Utility will take a minute or two to complete the task.
6. I don’t believe this step is required, but it makes me feel better and doesn’t hurt. Click on the volume name you entered in Step 3 (in the list under the flash drive’s name). Go to the Erase tab, make sure the Format is “Mac OS Extended (Journaled),” and click the Erase button.
7. Insert your Mac OS X installation disc if you haven’t already. A window should pop up with the contents of the disc. Double-click the “Install Mac OS X” icon and progress through the installer until you get to the screen that says “Mac OS X will be install on…”
8. Click the Show All Disks button and select your USB flash drive.
9. Click on the Customize button and a new window will appear. Un-check all of the items except “Essential System Software.” You may choose to check “Rosetta” and “QuickTime 7” since they are so small and might come in handy. Click OK and then Install. The rest of the process should be automated and might take between 30-60 minutes since USB flash drives are slower than internal hard drives. When all is said and done, you should find about 9GB of your 16GB drive has been filled.
10. Eventually, the installation will finish and it should reboot directly to the USB drive. If it doesn’t, restart the Mac manually and hold down the Option key to choose the drive yourself. This is how you will access it in the future, too.
11. Set up the fresh installation just like you would a new computer. Once you’re in, run Software Update a few times to get the latest patches and install any third party diagnostic utilities you may have. For example, Alsoft’s DiskWarrior is an invaluable tool that goes above and beyond what OS X’s own Disk Utility has to offer. This way both tools are available in one convenient place whenever you need them.

All done! That wasn’t too painful, was it? Yes, booting to the flash drive will be a tad sluggish, but it’s not meant to be used on a regular basis. This is mainly for diagnosing issues and trying potentially risky things in a virtual sandbox that won’t ruin any of your data. While you’ll hopefully never need to use it, having a bootable copy of OS X on a USB flash drive is a cost-effective, portable emergency tool for your Mac.

I had a guy bring me in an old Mac Book Pro that had a corrupted hard drive. I saved his Data but then realized his computer was so old that I was going to have trouble getting a copy of OSX installed. His computer was no longer supported on current OSX releases. To make things worse his DVD drive wouldn't read a install disk. So this post is the result of me finding a way to resurrect an old Mac Book Pro. I hope it will help someone else in a similar situation.

Note:

Before starting this tutorial, ensure that you have a USB drive with at least 8GB of storage as well as a Leopard, or Snow Leopard retail DVD or disk image. Grey DVDs that were included with a Mac at the time of purchase cannot be used to make USB boot drives as they do not include drivers for Macs other than the computer it was shipped with. In this tutorial I will be creating a Snow Leopard USB install disk. The steps are the same to create one for Leopard.

Creating a Snow Leopard USB Boot Drive Using Disk Utility

Start by launching Disk Utility on the Mac. To do this, you can either search for the application in Spotlight or find it in the Applications folder. Locate the USB drive on the left-hand side of the window and click on its name, not its partition.

Format the USB drive

• Click the Partition tab
• Under the Partition Layout header click on the 1 Partition option in the drop-down menu
• Click the Format drop-down menu and select Mac OS Extended (Journaled).

Bear in mind that this will erase all data from the USB drive, so backup any important files before proceeding.

• To format the USB drive drive, click the Apply button in the lower right-hand corner of the Disk Utility window.

Snow Leopard, DVD or Disk Image

• Locate a Snow Leopard disk image or DVD on the Mac
• If you're using a disk image, mount it to the desktop
• In the Disk Utility window, click the Restore tab in the USB drive's menu

In the center of the window you'll see two boxes: one labeled Source and another Destination.

• Drag-and-drop the USB drive's partition into the Destination box
• Drag-and-drop the Mac OS X Install Drive disk into the Source box
• At the bottom right-hand corner of the screen and click the Restore button

Disk Utility will restore the OS X Install DVD or disk image to the USB drive; this process may take anywhere from 20 minutes to an hour depending on how quick the Mac is.

Using The Snow Leopard USB Drive

Now that you've created a Snow Leopard USB drive, let's use it to install OS X Snow Leopard as well as access Terminal, Disk Utility, and other OS X utilities.

How To Make A Bootable Drive For Mac Os X High Sierra

• Power down the Mac and reboot while holding the Option key
• Select the OS X Install DVD from the boot menu using the arrow keys on the Mac's keyboard
• Select the language you'd like to use when prompted

Installing OS X Snow Leopard

To install OS X Snow Leopard from the USB drive, you'll need to reformat the Mac's hard drive. To do this, look towards the top of the screen and click on Utilities from the top menu and then click Disk Utility from the drop-down menu.

Formatting The Mac's Hard Drive

• Click on the Mac's hard drive name
• Click the Erase tab
• Select Mac OS Extended (Journaled) from the Format drop-down menu
• Name the drive whatever you'd like

Please note that all data on the Mac's hard drive will be erased, so backup all important files before proceeding.

• Press the Erase button to format the Mac's hard drive

Starting The Snow Leopard Installer

• Quit Disk Utility by pressing Command-Q on the keyboard
• Press the Continue button
• From the center of the window, select the Mac's hard drive
• Press the Install button

OS X Snow Leopard may take a bit of time to install depending on the Mac's hardware. Upon completion, the Mac will restart and prompt you to create an account.

Disk Utilities on the Snow Leopard USB Drive

How To Make A Bootable Drive For Mac Os X High Sierra

Additionally, you can access Disk Utility, Terminal, Safari (to access Apple help articles. not general browsing) and other Mac utilities from the Snow Leopard USB drive.

How To Make A Bootable Drive For Mac Os X On Windows Pc

Boot the Mac to the USB drive using the steps shown above and click on the Utilities button from the top bar. You can access all available utilities from this drop-down menu.

Drive For Mac Google

It's nice to have these utilities available to use from the USB drive, especially Disk Utility. For example, if you believe your hard drive has died or is corrupted, you can boot your Mac from the USB drive and use Disk Utility to check the the hard drive's SMART status and repair said drive.

OS X Snow Leopard USB Drive, Completed

In this tutorial, I've shown you how to create a bootable OS X 10.6 Snow Leopard USB drive. You can now use the USB drive to upgrade, maintain and restore Macs to OS X 10.6.