[Solved] Enlighten me please

The cable company sends encrypted TV signals to you so that people can't tap your wire for free TV. The cable box decrypts the signal. If you want your PC to do the same thing, you need the cable card, which acts as authorization for your PC to use that cable. An alternative is to plug your cable box into your PC's tuner, then have the PC control the box via IR, but this isn't as ideal as hooking it straight up to the computer. A good alternative is to request a cable box with FireWire support, then plug it into your computer, which will recognize it as a tuner and use it in media center or whatever you're using.

If you get a card with inputs, you can record 360 gameplay, but it would be delayed when it shows up on the PC in most cases, so you may want to use a splitter and also wire it to a TV so you can see it in real time.