I have Acer Aspire E15 notebook that had Windows 10 OS (64 bits) installed in UEFI mode with Secure Boot option turned on. It has InsydeH20 utility to display some firmware options upon booting.
I made a bootable USB for Ubuntu Desktop 18.04 (and then for 19.10) using Rufus with GPT/UEFI options and corresponding 64-bits ISO. So far so good.
Then I installed Ubuntu (just it, instead of Win10) - initially I tried 18.04 but due to some driver issues it wasn't a success then I re-made USB with 19.10 and it let me install Ubuntu.
The installation process itself was successful - I set language, time zone, my user/password, added internet connection and then it asked me to unplug the USB and reboot.
After rebooting it just couldn't find any bootable device. Ok, I plugged the USB with ISO again and then it somehow let me in under ubuntu/ubuntu
user. I didn't explicitly press Try without installing
option though. It just happened, maybe by default after some timeout.
There I was able to explore and mount partitions that intially were unmounted. I mounted 2 partitions - 1 small partition (537 Mb, only 9 MB used) with FAT32 filesystem (ESP, I guess) and then big almost 500 Gb (the whole disk) partition with Ext4 filesystem. Both are set to mount on startup. Ok. Seems fine.
Then I was able to reboot and see in the bootable (F12) menu two options - my USB and HD. Success? Not so fast. Choosing HD I logged in under my user, walked around, unplugged USB - it all was working fine. Then I tried to reboot again with unplugged USB - this time nothing in the boot menu (F12) and message like No bootable device detected
on the screen.
I haven't been able to log in the installed system under my user since then. I tried to turn off Secure Mode, played around with InsydeH20 boot options - no effect. I am pretty sure Ubuntu is there. Also when I boot in "Try w/o installation" mode I can set flags on partitions - System Partition and BIOS legacy - no effect.
I am puzzled. I see lots of similar topics but cannot find any solid definitive solution. It should work, but it doesn't work... How to make it all work? Very disappointing experience :(