In case anyone is interested, here is how to make a bootable USB drive out of the beta download. 0. This assumes you downloaded 10.11 beta from the App Store. It puts the installed inside you main applications folder. If you got it from some other source you may have differs results. 1. Format a USB drive. It must be at least 8gb. You can format it in disk utility. I did it in the new partition tab, HFS+ Journaled. Also, under options make sure it is set as guid. For simplicity I set the drive name to beta. 2. Run this command in terminal: Code: sudo /Applications/Install\ OS\ X\ 10.11\ Developer\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/beta --applicationpath /Applications/Install\ OS\ X\ 10.11\ Developer\ Beta.app --nointeraction 3. Put in your password. If you did it right, it should pop up this: Erasing Disk: 0%... 10%... 20%... 30%...100%... Copying installer files to disk... 4. Be patient. This WILL take a while. When the process is done, the terminal window will return to the prompt. 5. After this you can boot from the USB drive.