Using the U disk made by UltraISO to start, F12 key appears when USB starts

Failed to load ldlinux.c32
Boot failed: please change disks and press a key to continue

terms of settlement:

When UltraISO makes the boot disk, the write mode is changed to “raw”, and the system can start smoothly when it is installed.

reference material:

http://www.cnblogs.com/huadongw/p/6516637.html