Can't boot from USB

[alexmil]

Hi,
I installed some upgrades. I turned off the computer and the next day it Ubuntu wouldn't start (the LG screen would and then nothing).
I've tried to reinstall Ubuntu using a booteable USB but that won't work either (I've tried it using two different USB, and I've changed the BIOS boot order so the USB is first). I've noticed that when I disabled the "Ubuntu" option in the boot order menu, a error message appears when booting.

What can I do? Am I doing something wrong?

[yancek]

Your post indicates you have only Ubuntu installed and that you did 'some' upgrades. What specifically did you upgrade?
Did you originally install Ubuntu from a usb? If so, are you using the same settings in the BIOS you did then? Some computers will show a usb under HDD in the BIOS.


when I disabled the "Ubuntu" option in the boot order menu, a error message appears when booting.

Does that mean you have more than one OS? If so, what? Is this an EFI install? What is the error message?