I am trying to make my pc dual boot mac OS X Yosemite and Windows 8.1 after creating a yosemite usb boot drive using Transmac with YosemiteZone.dmg. I also created a partition and entered bios to change the boot option to "First boot: USB HDD" but i am still booting into windows 8.1 and i tried to use different usb slots and even USB FDD, USB ZIP and USB CD ROM. PLEASE i need help.