yes on most pc's the 'microphone\line in' setting is muted on the windows master volume, its muted by default, so not to cause feed back with the speakers.
also use the sound recorder program in windows, to test your mic is working, lets you record sound from your mic, check your mic is working, if this works looks like its setting in your cam software.
what ever software your using , it should have a test function, so you can test the mic and speakers,
if still not working checked you plugged the mic in the right hole
also check the settings in windows sound and audio icon, they are not muted or volume is not too low.
