You will also need an application that captures video - along with the hardware
The USB Capture device includes the software.... "Include Professional and easy to learn & used video editor software: Ulead Video Studio 8.0 SE DVD" It does sound like a Chinese version however
You will see the captured video in a little video window on the PC. Now if you want to use the XBOX monitor and capture device at the same time, you will need a VGA splitter. One signal to the TV/monitor and one to the capture card.
The Hauppauge HD PVR can do the trick as it takes the component stream from a video source, compress it to H.264 and then push it to a computer via USB. You can also try the Intensity Pro capture card. Here are the technical specs: Intensity Pro Tutorial.