I am using a new Sony Vaio PC and keep getting "static" when I add audio to my PowerPoint presentation. Us old guys know this sound as RF. I have tried turning off flourescent lights and changing where the PC is plugged in so it won't be on the same line as the battery backup. Still getting the static. The microphone has a tight plug-in. It is a Sony ECM-170. I would really appreciate some help on this. Thanks.