Click on “Erase” to format the USB drive.Choose “Mac OS Extended (Journaled)” as the Format, and name the USB key what you want.Select your USB drive from the left side of Disk Utility, then click on the “Erase” tab.Next, we format the USB flash drive, this will become the bootable Lion installer: Open the “Contents” directory and then go into “SharedSupport”ĭouble-click on “InstallESD.dmg” to mount the Lion disk image onto your Mac desktop, it will show up like the image below.Right-click (or control-click) on the “Install Mac OS X Lion.app” and select “Show Package Contents”.If you have anything stored on the USB flash drive you’re going to lose it, so be prepared for that and back it up.įirst we are going to locate the Lion InstallESD.dmg file and mount it: We’re going to assume you already have Mac OS X Lion downloaded from the App Store, if you don’t, do that first. How to Create a Bootable Mac OS X Lion Installation USB Drive Download Mac OS X Lion from the Mac App Store ($29.99).8GB+ USB flash key drive, these are cheap and ubiquitous on.A Mac with Mac OS X 10.6.8 so you can download and access Lion.This is pretty easy to do, but I have made the walkthrough as simple as possible with plenty of screenshots, so just follow along the instructions.

This is similar to the process of making a bootable Lion installer DVD, but I prefer a USB flash drive because it’s faster, smaller, and I have a MacBook Air so an installation DVD isn’t too useful for me. I’m going to walk through the process of making a bootable Mac OS X 10.7 Lion installation drive out of any USB flash drive key.

Mac os lion bootable usb