Help- How to Record TV??

[Motam.co.uk]

Hi, just wondering if anyones knows how this would work.
basically what I am trying to do is record TV on my PC, signal from my virgin box.

Current setup
Vista based PC
Virgin Media Box

just wondering what i need....do i need a tv card? how would it all work..what do i have to connect to make it so i can record onto my Hard Drive.

basically instead of using VHS / DVD recorder, i want to use my pc to record programs i might miss.

Help Please