What port do I use to send information to a piece of hardware?

[brreaker]

This isn't really related to windows 7 (although I am using it and doing my programming based on it), I have a simple circuit consisting of a battery, a transistor and an LED.
I want to use the transistor to light up the LED by sending voltage to a cable. I tried using the USB port, however, it has a positive, negative and 2 data cables. Both cables are continuously sending data, so I cannot make the voltage 0 on any of them and stop the LED.
I've heard I must use a printer port, or an ATA connector, I am fairly unsure of what control software has over hardware. Any help is greatly appreciated!
Later edit: I mean other than using an USB interface

 

[LMiller7]

With a 16 bit OS or even Windows 9x this would be a relatively simple task. But with the NT platform direct access to hardware is the exclusive domain of system level code. Actually it is done by the HAL but that can only be called with system level code, or in other words a device driver. Writing a device driver is not a simple thing.

You really need to find a device driver that can do what you want.

 

[brreaker]

I see, thank you for the time you took to reply. However, I understand that using an ATA connector I can trick the pc into thinking it is sending data to the CDRom via VB. But I think the safest and easiest way is buying an USB interface that has a microchip and allows you to control hardware via programming. At 30 bucks they are fairly inexpensive. Thank you again for your time.