May I ask some questions?
Which WinTv card do you have installed in your machine?
Is it for analog or digital television?
When you connect the cable from your digital cable box to the
card, do you mean you are connecting it to the WinTv card?
Is the cable from the digital cable box carrying a cable tv service
in digital format? If so, and you have an analog WinTv card,
then as you have seen, it is not going to provide you with a signal
which your card can decode.
Instead of trying to connect a cable tv cable, why not try connecting
up a set-top tv antenna and try tuning your card with xawt to a local
station? If you do not have an strong local stations, then you will
have to connect up to an external antenna.
Doing a full install of an OS on a computer because an application
does not work, is like taking a an automobile apart and reassembling
it because you can't tune in to a particular station on the car radio.
And why are you having such difficulties installing lirc?