Question about SoftWare called CamStudio

I ran across same problem.
go to audio options>audio options from speakers>manual search under recording config
it will walk you through a sound test to determinine your recording line.
I had to try each one (6 total) and number 2 was mine using a creative audigy ex platinum sound card. I just did one minute captures to test it out.
make sure your sound card or onboard sound controller is selected in the top drop down box in that sub menu.