Hi!
I followed as what Tony said to do and created the USB, but when I tried to boot it, and with boot flags such as -v, -s, -x, and nv_disable=1, it all didn't work. El Capitan is working just fine right now.
SPECS:
-intel i3 3.7Ghz
-Nvdia 750 Ti FTW
-SSD
-MSI B85m Gaming MOBO
Heres a picture...