Which System76 model? How is the install media created? Presumably it's a USB stick, but how is it being created? The easiest and most reliable is to use dd. Livecd-tools is also reliable but has a number of options required to boot UEFi systems. LiveUSB Creator should work. Everything else is prone to failure. CentOS 6.4 is kinda old for new hardware. You're better off looking at CentOS 7.1. Chris Murphy