He's trying to plug the wired Xbox 360 controller into the original Xbox and use it as a controller, right? That's what I tried.
I have a wired Xbox 360 controller, I bought a cheap $5.00 Xbox to USB adapter (supposed to be so that you can use USB keyboard/mice when you convert it to a Linux box) and I plugged them in and it didn't work. The ring of light that denotes what controller you are flashes once and the goes out. After that, I can't do anything. I tried it. Doesn't work.