recording from a pc

I am new to Audacity and so far have recorded my old audio tapes to my PC hard disc.
Now I want to record radio programmes from my PC.
Is it possible to have the PC streaming the radio programme and have Audacity running on the same PC to record the radio programme.
If it is possible can someone explain in easy english as I am a silver surfer, not that used to computers.

There are different methods depending on which version of Windows you are using.
See here in the manual for instructions:

If you are using Windows Vista or later, use the “WASAPI” settings as described in that article.