Drag the basesystem dmg icon into the source field on the right if it isn t.
Turn the power on, hold down the Option key, and select the drive from the list that appears on the screen. Create a bootable install usb drive of mac os x 10 10 yosemite step 1 reformat your usb drive. To use it, simply connect the drive to the target Mac with the power off. Once it's done, you have yourself a bootable Yosemite installer drive. It should say "Copy Complete" when it's done. The process of readying the disk as a bootable drive will begin.You will be prompted to enter your system password - the password you use to update apps on your Mac, or to login at boot.Paste that text into the Terminal application and hit the Return key.Copy the following text: sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia -volume /Volumes/Installer -applicationpath /Applications/Install\ OS\ X\ Yosemite.app -nointeraction Remember how I mentioned it was important to remember what your hard drive or USB thumbdrive was called? If you didn't call it "Installer," you'll need to change the pathname where it says /Volumes/Installer to the name of your drive.Open the Utilities folder if it's closed.This requires you to work in the Terminal application.
The next step is to prepare the disk to operate as a bootable drive. To make the drive bootable for the Yosemite installer Format it for "Mac OS Extended (Journaled)." Click the Erase button.Remember it though, for the next step in our procedure. For the purposes of this How To, I've named it Installer. Name the drive whatever you'd like, but I'd recommend using one word, easy to remember. Select the hard drive or USB thumbdrive from the list on the left hand side of the Disk Utility window.Attach the drive to an available USB port on you Mac.You'll need to make sure that external hard drive or USB drive is properly formatted for the Mac. After it downloads, the installer app may automatically launch. The installer is free, though you'll need to be signed in to the Mac App Store to download it. To download the Yosemite installer, click here.