I have just received a Dell XPS 13 9350 and it is the Developer Edition with Ubuntu 14.04 preinstalled in it.
I have deleted the default Ubuntu install and I have installed Windows 10.
Now I have entered Ubuntu 16.04 LTS pendrive and when I want to install alongside with Windows 10 it doesn´t give me the option and I didn´t want to manually partition the SSD as I don´t know what to do next.
I would like to have a dual boot of Windows 10 and Ubuntu 16.04 LTS.
Note that I have also tried doing this in Legacy mode as I am working in UEFI mode now with secure boot.
I am asking for help to dual boot both OS, thank you all.