Once you've you done that, click 'Erase' again and confirm. In the format box click 'Mac OSX expanded'. Then, on the right menu tab click 'erase'. In the left-most window select the pen drive you've insert in your Mac. Open Utility Disk – the app that appears from your search. Then go to your search box at the top of your desktop and search 'utility disk'. Step 3Ĭonnect an 8 GB or higher storage pen drive into the USB port. To do so, click the 'menu installation' of OS X, then go to 'finish installation' of OS X. When the download is complete, the installation guide will start automatically. You'll be able to find the OS X El Capitan available for download in the store. Step 1Ĭlick the Apple icon on your desktop, then click 'App Store' to access your Mac Apple store. Below I'll explain how you can set up a storage drive with Mac's OS X El Capitan. Did you know that you could keep an OS on a storage drive, just in case? You never know when you might need to (re)install an OS on the go – I know I've had to.