Automatic detection of new hardware (serial port)

In my program I have a drop down box which I populate with the available COM ports. I currently have a button which I need to press each time I want to refresh this list (which I need to do when a new USB to serial converter is plugged in, for instance).

Is there a way to do this automatically? I mean to capture an event that occurs when new HW is plugged in which would trigger the execution of the refresh function, without having to press the function.

Best regards,

Cristian