If you bought the Pi 3 for coding and programming specifically, then the Windows 10 IoT Core is the best option to go with. Don’t get confused with the name because the Pi will not support the same Windows 10 version we use on our desktop PC, but uses a slightly simpler and slimmed down version of the OS.

Windows 10 IoT Core is best for prototype development of connected devices
Projects like automated robots, home automation system, building smart gadgets, etc. can be successfully completed by the support of this Operating System
It also works on Pi 2, DragonBoard 410C, and MinnowMax Boards     
Applications like a web server like sensor to a temperature reader are best built with this OS for Pi 3
You need to install Visual Studio on your Windows Raspberry Pi PC which is necessary to control and program your device through it if you want to use Windows OS