try this: go to control panel> sounds and audio devices(classic view)>advanced> and on general volume tick with out sound for microphone (if there isn't a microphone option go to options>properties> and select microphone)
![[Image: attachment.php?pid=635786]](http://shoutbox.menthix.net/attachment.php?pid=635786)
this should low the feed back but it won't fix all you should put the webcam at distance from the speakers