To automatically start a program in Windows 11, you can go to Settings > Apps > Startup and turn on the toggle for the desired app. Alternatively, you can place a shortcut of the program in the Startup folder located at

%userprofile%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

DCS-BIOS connects custom-built control panels powered by Arduino microcontroller boards to the flight simulator DCS World. It can also be used by other programs to interface with DCS.

At the very basic level, it is an Arduino Library that will recieve and send data to and from your PC running DCS World over USB.