audio absent on trial video tutorial

I am ready to try the trial version prior to purchasing pianoteq.  The video tutorials have no volume.  As far as I know, everything I'm supposed to do is done properly.  Anyone have a clue how I get volume.  Speakers plugged in, volume is set on high on video, volume on high on computer, volume on high on speakers--no sound.  Of course I'm not leaving everything on high.  It doesn't make any sense to me.  Help!  Don