It doesn’t matter whether you use macOS or Windows 10, it’s just a matter of time until your device will refuse to start, which could happen for many reasons, including (and not limited to) file corruption, hardware failure, and buggy update. If the unexpected happens with an Apple computer, you can use a macOS bootable USB with the installation media to repair it.
This is one of the main reasons why you should always consider making a macOS bootable USB when your device is working properly. However, if it happens that none of your devices (MacBook, MacBook Air, MacBook Pro, iMac, Mac Pro or Mac Mini) aren’t working when you need them the most, then you can use a PC to rescue your Apple device. You can use a Windows 10, Windows 8.1, or Windows 7 device to quickly create a USB bootable installation media to reinstall macOS Catalina or Big Sur on your Mac.
In this guide, you’ll learn the steps to create a macOS Catalina bootable USB installation on Windows 10, which you can use to reinstall or upgrade the Apple OS.
Before proceeding, you’ll need the following:
- Broken Mac computer running macOS (version 10.12, 11, or later).
- Trial copy of the TransMac software.
- One high quality USB flash drive with 16GB of storage.
- Copy of macOS (DMG file).
Create macOS bootable USB installation media
To create a bootable USB drive with macOS, use these steps:
Once you complete the steps, you can now insert the USB flash drive on your Mac computer to install, reinstall, or upgrade the operating system to the latest version of macOS, which can be Sierra, Catalina, Big Sur, or higher.
Create a GPT partition on USB flash drive
If the USB flash drive is not working with TransMac, it could be still a partition problem. In this case, you may need to redo the entire process again. However, this time use the following steps to use the Diskpart command-line utility on Windows 10 to create the appropriate GPT partition, and then follow the above instructions.
To create a GPT partition on a removable drive, use these steps:
Once you formatted the USB flash drive with a GPT partition, you can use the instructions mentioned above to use TransMac to create a bootable media, but this time skip the steps No. 5 through 10, and continue on step 11.
After the process completes, which can take up to an hour, connect the USB flash drive and power on your Mac holding down the Option key, select the USB drive to begin the installation of macOS.
If you’re having problems creating the bootable media, you can get a USB flash drive that comes with macOS Sierra, El Capitan, Catalina, etc., on it with the link mentioned below. (I haven’t tried it personally, but it’s worth the try if nothing works.)