I just got a new laptop just for Ubuntu (Acer aspire e15). Upon installation, I forgot to disable secure boot from Windows and installed Ubuntu 16.04, wiping out windows 10. Now Ubuntu won't boot and Windows 10 is gone. I tried boot-repair and still nothing. Disabling secure boot through Bios is not an option. Anyone can help me?
Remove all boot media. This should cause to display "no device to boot to" or a similar message and forces a full POST rather than fastboot sequence after reboot. You can access UEFI setup at POST and disable secureboot that way. Do not forget to remount all your boot media.