Question

HOW TO MAKE USB BOOTABLE ?

Answer 1

if it is the case of ubuntu in system tab there is app called usb starter disk for others google it

Answer 2

Indeed, if the case may be you are trying to install a Linux distribution (Unbuntu, Fedora, etc.) you can install the OS onto a USB, plug it, restart your computer, and when you get to your BIOS splash screen (foirst thing you see when you start your computer), enter your BIOS setup, and set your computer to boot off of the USB instead of, say, your main RAID drive. All you have to do after that is just save it, and restart your computer again. If you have any further questions, feel free to ask :D

Answer 3

u need live usb creator