So, to make BIOS correctly detect your USB drive and pick it to boot the computer, make sure that you choose the USB as the boot sequence priority. Solution - You must configure the boot order sequence in BIOS settings so that your computer can make its own decision which physical device it should select to boot from. If necessary, find another working computer and repeat until completely exclude the factor of a not working port. Solution - Try to connect the USB drive through every USB port that is available to use on either a desktop or laptop. USB Connection Issues Resulting from Loose or Broken USB Port You may perhaps have attempted to reconnect the USB installation media for several times, but why the computer still doesn't recognize it? Answers are now given.
Here we have many thinkings on solving a bootable USB not working problem, which appears to be missing somewhere. But here comes the problem, you took the right steps and enter into the BIOS environment with success, only see that the bootable USB drive not showing up there! Why doesn't BIOS recognize or detect the bootable USB flash drive then? Why Doesn't the Bootable USB Drive Show up in the Bios
