Russian (Russia) 
English (United Kingdom) Faced the fact that the BIOS stopped seeing the bootable USB flash drive and DVD.
What settings of the flash drive recording I just did not try. As soon as I did not burn a DVD with images, and went through the BIOS settings, but it did not give any result.
The reason was discovered by accident - the webcam was interfering with the boot, which was connected to check ZoneMinder.
These are the incidents that happen 😄.