In this video, you will see how to install windows server 2016 in Oracle VM VirtualBox.
First, you need to download windows server 2016 iso file from the official Microsoft website or any other website available on the internet(you just need to google it). It is free of cost.
Make sure that you have installed Oracle VM Virtualbox on your computer.
If you need to know how to install a VM on your computer? feel free to comment I will post a video on that too.