Audacity 2.0.3 and Windows XP

I downloaded Audacity 2.0.3.
I could record voice from a desk-top mic perfectly but could not record from online radio.
I could not find any option for “Stereo mix.” Now everything is gone and I can’t record from anything despite the fact that I didn’t ( consciously) change anything on my computer. I have Windows XP.

Mattie Lennon

Please see this tutorial in the manual: