I tried to install Ubuntu on a Dell Inspiron N411Z, as the only OS, deleting the Windows 7 it had on it. The installation finished correctly, and it prompted me to restart the computer. When restarted, a message shows up saying Operation System not found, and it takes me to the BIOS menu. I used Rufus 3.21.1949 portable to create a bootable USB. (My USB being 7.8 GB). I tried with a MBR and with a GPT partition, and neither worked.
It's the first time I tried installing an OS. Do you have any idea what might have gone wrong?
Here are some images of the Bios:enter image description hereenter image description hereenter image description hereboot settings