Insert the USB drive that you’ll use to fix your installation of OS X. (If you want to support the developer, you can purchase the full version.) Quick note: TransMac is a paid software, but it has a 15-day trial solution that gives us more than enough time to move the DMG files to the USB drive from Windows. Use these steps to set up a USB drive with a GPT partition: To do this, you’ll need to use the Diskpart command-line utility on Windows 10. Create Mac OS X bootable USB installation mediaīefore using TransMac, you first need to partition your USB flash drive with a GPT partition, as a normal MBR partition may not work. 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. One high-quality USB flash drive with 16GB of storage.Requirementsīefore you dive into this guide, you’ll need a few things: These instructions will also work for Windows users running Mac OS X on a virtual machine and needing to upgrade to the latest version. However, if you find yourself in a scenario where your device (iMac, MacBook Pro, Air, Mac Pro, or Mini) is not responding, and you happen to have a Windows 10 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. This is why it’s recommended that you make a Mac OS X bootable USB when your Mac is in working conditions. You’ll also need access to a Mac running Yosemite that includes an existing Recovery HD partition.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. To create a recovery disk, you need a USB flash drive or an external hard drive that has at least 1GB free space. The simplest solution is to put an external USB drive or SD card into service using the OS X Recovery Disk Assistant. However, if your Mac is not online, or if you’ve upgraded an older Mac to Yosemite, that method won’t work. This recovery system is stored on a hidden partition on your Mac’s hard drive - but what if something happens to your hard drive? Well, if your Mac can’t find the recovery partition but it’s connected to the Internet via either Wi-Fi or a network cable, it’ll start the OS X Internet Recovery Feature.

Start your Mac and hold Command + R to go into recovery mode, from which you can start Disk Utilities, restore from a Time Machine backup, or perform a clean install.

OS X 10.7 Lion did away with recovery disks, and these days, Apple provides a built-in recovery system within Yosemite.

Creating an os x boot disk