If, however, you only want to reinstall macOS once on one computer, you don’t have to use a carrier. You might want to keep installing files on an external drive if you think you might need to install the operating system multiple times or on different computers. In the following instructions, we will use a USB flash drive as an external carrier example. Give your disk the name of the operating system, e.g., Sierra, Mojave, Catalina. Whichever type of drive you choose, make sure that it has at least 12GB of free memory.īear in mind-when you download an installer, the disk will be reformatted to suit the operating system you’re trying to run. Use Terminal to create a bootable installerįor your external disk to run macOS, you can choose as a USB flash drive, as well as an SSD or HDD.In this article, you’ll find detailed instructions and answers to your questions on how to make a bootable USB on Mac. You can try out the different tools for free, so download it, and see what you think. MacKeeper can do everything from finding malware to updating your apps for you. When the scan is finished, review the results, and click Fix items safely.Select Find & Fix from the menu in MacKeeper.You can do that with MacKeeper’s Find & Fix feature, which will scan your Mac for a variety of different problems. It’s a good idea to keep your Mac optimised when you’re asking to create a bootable USB drive. It’s a handy appliance-even more so if you use a small external flash drive that you can carry in a pocket.

You can also use it to reinstall the operating system on a Mac that won’t startup. Such a tool allows you to install any version of macOS on multiple Apple computers easily. Why would you want to create an external boot drive for your Mac? A bootable macOS (previously, OS X) install disk is a portable device containing all the necessary installation files for a selected version of macOS.

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