OK guys some say there is no Mic Boost or adjustments for your mic in Vista. I say try this. Open Control Panel then Open Sound now there are tabs at the top Choose Recording Hi lite the Mic your using some have more then one. Now click the Properties Button, this opens the Mic Properties, there is a Levels tab, click that, adjust the Level to about 90 or so. Click Apply then OK your mic will be louder now.
NOTE: In some cases you MUST CONFIGURE your mic to work in windows first (i.e. speech recognition)