If you watch to watch over-the-air, now, and i-cable TV on your computer through a TVTuner card, this is what I've learned.
First, your flat should have at least 1 outlet at the wall, with 2 wires sticking out, one for FM and one for TV. Our flat has 2 such outlets.
Also, I'm describing setup for the cheap TV tuner card that came with my new computer.
To watch over-the-air (analogue) channels like Pearl, World, Jade, etc., connect the TV wire directly to your TVTuner card. Or is you have i-cable, that connects to your tv, buy a splitter (about 5$HK) and run your i-cable output to the splitter, then buy 2 cables and from the splitter, connect one to your tv (a very short cable will do) and buy a long cable to connect to your computer. My computer is 30 or so feet away. Plug the cable into your tvtuner card, run Vista Media Center, tell it you have an antenna (NOT a set-top box), and it will scan and find 24 channels. These are the over-the air channels.
To get now on your computer, buy a 'composite' cable, i.e, and ordinary Red/White/Yellow cable long enough to reach from your now box to your computer. The now box has as second set of R/W/Y outputs, so connect those to your TVTuner. Yellow is video, R and W are audio, but TVTuner cards and sound cards require the R/W nines to be combined into a mini-stereo jack, so you need to get one of these. Male stereo on one end, female R/W one the other.
OK, go into media center and this time tell it you have it set-top box, it will find it right away and start playing whatever now channel you are currently tuned to. What follows is a mandatory exercise in technical insanity which I will describe in a reply to this message.