How to add Windows 10 to Grub menu in Ubuntu 17.04

I've installed Windows 10 and then installed Ubuntu 17.04.

I've also disabled fast startup and UEFI secure boot.

When I start ubuntu the Grub display is shown, but there is no Windows entry.

I've tried to use:

sudo update-grub
sudo grub-install /dev/sda4

(sda4 is where the Windows Partition is at)

But none of this commands worked, the first didn't list the Windows 10 partition and the second one prompted an error message.

I've also tried to install boot-repair but I couldn't launch it in Ubuntu 17.04.

I've installed Grub Customizer but it does not list any Windows partition and I didn't found how to add a new one.

At the moment in order to run Linux or Windows 10 I have to enter the Bios and select the desired OS partition which seems very cumbersome to do every time I need to do this.

Any suggestions on how to fix this?