Windows 10 and Ubuntu dual boot options missing

[Jeremin]

Hello!
So my main OS is Windows 10. Today I installed Ubuntu to second partition. Now if I want to boot to Windows 10 I need to change to UEFI mode from BIOS and if I want to boot to Ubuntu I need to change it to Legacy. How could I add some kind of menu to select the OS into I boot every time I start my laptop. Like GRUB bootloader. (GRUB won't show up when booting to Ubuntu). None (UEFI and Legacy mode) displays any kind of selection. Just directly boots to OS.

Also while installing Ubuntu I didn't had the option to install Ubuntu alongside Windows 10 so I used 35 GB for system and 4 GB for swap.

 

[Jeremin]

Booted to UEFI Windows 10, removed partitions (Ubuntu), made new partitions, made new bootable USB, changed boot priority, booted from USB to Ubuntu installer, installed alongside to Windows 10, after installation no GRUB, booted straight to Windows 10, cmd (run as admin), use: bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi After reboot I was welcomed with GRUB.