I am not able to create a USB stick that is recognized by the BIOS and bootable. I tried Unetbootin, the terminal command dd and also mkusb. I tried several USB sticks and tested for recognition by the BIOS on a Shuttle Barebone PC and also an ASUS laptop, both with Linux 18.04 on them. Both are not able to recognise the USB as bootable, or if recognised, trying to boot from the USB results in the BIOS startup menu just re-appearing.
I was successfull creating a bootable USB with clonezilla to check whether my laptop has a problem with recognizing USB sticks in general, which is obviously not the case.
Creating the clonezilla USB involved special commands for making the USB bootable (here).
I especially wonder why copying the .iso from here with dd to /dev/sda (without partition number) and /dev/sda1 (e.g. to the first partition) is not working.
Is there a definite way to create a bootable USB with the .iso for 4.1.3. which is bulletproof?