Well, I faced this situation recently during UBUNTU installation from flash drive. Fortunately I have another laptop with a different BIOS which helped me solve the problem.
Most pendrives are shipped with USB-FDD formatting which may prevent you from booting or determining the booting sequence in BIOS. Fortunately, there is a free solution.
Most pendrives are shipped with USB-FDD formatting which may prevent you from booting or determining the booting sequence in BIOS. Fortunately, there is a free solution.