Lost sound

I need help with restoring my sounds. I think I lost sound when I installed
yahoo call so as to talk to a friend over the internet. Since then I have not
been able to listen to radio, my playlist or CD even thought it is playing.
My Toshiba Satellite 2400-S202 (2002) uses the Yamaha AC-XG Audio device. I
have troubleshooted and the response is that it is functioning well.
However, when I administered a diagnostic tool I got this message after
testing for sound: DirectSound test results: Failure at step 19 (User
verification of software): HRESULT = 0x00000000 (error code). Can someone
help figure out how to restore my sound? I cannot get an update for Yamaha
audio device.