
Once the USB drive has booted, select Disk Utility from the Utilities window, choose your Mac’s startup drive from the list, and click Erase.Īlso, how do I do a clean install of OSX from USB?

Similarly, how do I install OSX Catalina on Macbook Air from USB? Use the mouse pointer or the arrow keys on your keyboard to select the disk called Install macOS Catalina in the drive list that appears on the screen. Once you have your bootable installer ready, it’s time to move to the next step. On a MacBook or Mac desktop computer, download the version of macOS that suits your needs.

How do you make sure your Mac is backed up?.
