Here is how to startup vm (headless) in virtualbox at windows boot time

@echo off

cd C:\Program Files\Oracle\VirtualBox\

VBoxManage startvm "Cisco" --type headless

NOTE: Cisco is a virtual Machine

Save as start.bat and then on windows computer

Start+R button, and write shell:startup

and paste that .bat file in directory

How to shutdown VM (guest machine) in proper way and  shutdown Windows OS (host machine)

@echo off

cd "c:\Program Files\Oracle\VirtualBox\"

vboxmanage controlvm Cisco acpipowerbutton

sleep 60

shutdown -s

these are all two scripts and should be saved as .bat file, and

later can be converted to .exe

Best of luck