How to turn Lenovo computer into boot USB flash drive? Which of the following options should I choose to start?

The first item is the optical drive, and the second item is the hard disk.

Select the hard disk of the startup item as the USB flash drive in bios, and then return to this option. Otherwise, there should be something wrong with your USB flash drive.

1 in the motherboard bios settings. Find the first boot and set it to USB-FDD or USB-HDD.

2 First, insert the USB flash drive into the USB socket (it is best to insert it into the USB interface behind the host and unplug other USB devices temporarily), restart the computer, press Del on the self-check interface of the boot system to enter the BIOS settings, and find out where the computer boot settings are, such as "advanced BIOS function" or "boot device priority". Select "USB-HDD" or "USB-ZIP" as the first boot device according to the self-made boot USB disk format, then press F 10 to save, press Y to confirm, and press Enter to exit BIOS setup.

Due to different motherboards, the method of choosing USB boot is different. For some new motherboards, the choice of "USB-HDD" is to set the item "First Boot Device" as "Hard Disk" in "Advanced BIOS Function"/"Boot Order &: Floppy Disk Settings", and then select your USB flash drive in "Hard Disk Bot Priority" (the USB flash drive cannot be started until it is plugged in.