USB making

Hello

My computer died and I try for several of time to make a bootable USB drive cu repair my mac but with Unibeast it take at least 1 hour to make the USB drive and when I put it into mac it give me an panic error.



I tried on 3 different USB drives, downloaded again El Capitan and Yosemite from Appstore and still goes on.

I try to do this USB drive from a genuine MacBook Air 2013.

What can I do to resolve my problem?

Thanks in...

USB making