Windows 7: Windows Media Center Live TV Question....

Quick question. It may have been answered before. If so...link me.

But is there a way to use Windows Media Center to watch Live tv WITHOUT having to buy the adapter thing that it needs? Is there a program to download then just BOOM...i can watch Live tv??? Just wondering since there are ways to do alot of other things out there. Just thought it may be possible.

[Edit] I may have said that wrong. I mean tv as in my cable tv. I know you need to buy some kind of adapter then you can watch..play..pause Live tv and such. Is there a way to do that without buying a adapter somehow?