recording problem

My first post:
I have used Audacity to record a radio music program (from the UK) successfully for about 2 years but recently something changed. It seems as though the sound/music recorder function of the program is using my computer’s microphone input to record the music. Thus, the playback sounds as if it were recorded in a tunnel. I cannot figure out what setting in Audacity changed or which settings I should attempt to reset. Can anybody help with this?
Thank you.
Reg B.

What are you trying to record? Internet radio playing on the same computer? If so, see: http://manual.audacityteam.org/o/man/tutorial_recording_computer_playback_on_windows.html

If you need further help, please state which version of Windows you are using and the exact three-section version of Audacity from Help > About Audacity.