Install Ubuntu 15.04 on Windows 10/VirtualBox

Install 64-bit Ubuntu 15.04 on Windows 10/VirtualBox
http://android-er.blogspot.com/2015/09/install-ubuntu-linux-on-windows.html

Related: Install Ubuntu 16.04 LTS on VirtualBox/Windows 10
http://android-er.blogspot.com/2016/04/install-ubuntu-1604-lts-on.html

source
ubuntu