how to get my tv on my pc screen

hey guys,
I can easily get my pc to show on my tv screen, but I was wondering if I can do the opposite and somehow get my tv to show on my pc screen, so I can watch tv on my comp basically

I have the VGA connection cord for pc to tv so if anyone can help me out would be much appreciated.

 

I think you need Media Center, or a TV Tuner. My brother is able to record TV or watch whatever is on at the moment using his.

If you have the available PCI Slot, it's something to look into. It's like Tivo but on your PC.