Ok so this might seem like a very common problem but I couldn't find answers anywhere for my specific case. I freed and created some unallocated space from my C:\ drive in windows and it all went well. But while installing Ubuntu 16.04LTS, this popup came up(sorry I am not allowed to embed images yet.): Popup.jpg
It means my windows is installed in BIOS mode, and I didn't want to force install Ubuntu in UEFI by clicking "Continue in UEFI", so I clicked "Go Back" instead. Installation loaded for a while and then it automatically moved forward to next step, I assumed that it'll now continue installation in BIOS mode, but now it only detected FreeDOS(my laptop shippped with it, its on /dev/sda1), and not Windows 10(which is on /dev/sda2), and gave me the option to "Install Ubuntu alongside FreeDOS" only, not windows10. I unfortunately considered that GRUB will detect it later and chose "something else", created / and swap from my unallocated space, and installed Ubuntu. But after installing GRUB isn't detecting Windows 10.
I confirmed my Ubuntu installation too is legacy BIOS as there's no /sys/firmware/efi directory, so it shouldn't be BIOS vs UEFI problem, also, my BIOS has "Legacy support" enabled. Also, os-prober only shows FreeDOS, as below:
/dev/sda1:FreeDOS:FreeDOS:chain
I also tried Boot-Repair and performed "Recommended Repairs", but nothing changed. I tried running startup repair from inside windows 10 setup from bootable USB, but it couldn't fix it. I've got no idea how to get this working, is there something I am missing? Any help is greatly appreciated !
EDIT: Ok, so I also tried adding custom menu entry to 40_custom in /etc/grub.d/ as below:
menuentry 'Windows 10' {
set root='(hd0,msdos2)' //as windows is on /dev/sda2
chainloader +1
}
but still, sudo update-grub2 shows:
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.4.0-45-generic
Found initrd image: /boot/initrd.img-4.4.0-45-generic
Found linux image: /boot/vmlinuz-4.4.0-31-generic
Found initrd image: /boot/initrd.img-4.4.0-31-generic
Found FreeDOS on /dev/sda1
done
No windows :(