After installing Ubuntu 16.04 LTS from USB drive to unallocated space on my hard disk, when I reboot the computer it boots directly into Windows 10 without showing a dual boot option.

I followed the instructions given here: everydaylinuxuser.com. I had previously set UEFI to legacy BIOS and reinstalled Windows 10 together with Windows 7.

I then decided to install Ubuntu. I have reinstalled Ubuntu several times but I still cannot create a dual boot option on restart.

Does anyone have a solution for this problem?

You can see my disk partition layout here: