on vista ur MIC is automatically muted by default not to playback..because it was a nuisance..who wants to hear what u say through ur speakers? rather than hear the person ur talkn to..
so to straighten this out right click on ur volume control
in control panel>>>in control panel home>>>click hardware and sound>>>>>>sound>>click on the playback tab>>set speakers as default..and hit properties..click on the levels tab
make sure everything is unmuted...
and set everything that was at 0 to 50..for the sake of this..
main thing is ur mic and pink line in, black line in, etc..
hope this helps...sorry for the kind of confusing directions