I've installed ubuntu 18.04 lts alongside windows 10. I partitiond a disk of 80 GB on windows. Then i booted ubuntu from a usb pendrive, and did the following steps. 76GB partition for the root system, logical, ext4 system. Then another 4GB for swap area. When I wanted to continue, it said:
No partition detected for EFI, your system might not boot. Please create a partition for the EFI or continue at own risk.
So I went back and created a EFI System type partition with 200MB as recommended. Then the installation went properly, but after it, when the system restarted the boot failed with the following message
Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key.
What I tried: disabling the UEFI/Legacy mode.
My boot order: 1)HDD 2)CD/DVD 3)PXE network
I also did a boot info with the log at: boot log
I didn't find any other suggestions with this topic, so I'm asking for your help. I don't want to loose data and programs on win10 if it's possible, but I would definitely like to have a dual boot option with Ubuntu being the other OS
EDIT: So I discovered in GParted that the boot flag from sda1 ntfs (Win 10 boot) came off, so I added it. Now I can access WIN 10, but still not Ubuntu.