It's not overly important but since I noticed the header a while back myself I figured I will plug in a usb port slot plate in the riser module and have more usb ports in the back because now I have printer, harddrive, mouse, keyboard, wireless adapter and webcam. But I was thinking of connecting another usb harddrive or 2 but I dont want cables in the front. Its not a big deal. I got the computer cheap and I chose it mostly for the quietness and size. I'm actually using it as a media center and it works good even in 1080p video. I would like to figure this out cuz I don't want to hook up a usb hub if I don't have to. I wonder if lenovo support can help me? I'm not the original owner of the pc as I got it at a store as a return asset sale.