First off your tool for fixing this is sound recorder. Much easier to play with settings, try a test recording, playback, then readjust than any other method. In Windows XP sound recorder can be found at start/programs/accessory's/entertainment/sound recorder.
Next, try different mic positioning. Farther away for starters.
Then play with some of the other options. If you have a advanced tab in volume controls for mic, go there and see if you have a "boost" option. Then work with the mic input level and the recorder until you start getting good sound.
Then come back and test it in game.
A mic sock is a good idea if your getting wind noise (like it sounds your getting)
Setting mic so its not in front of your mouth, but rather off to the side often also helps.
Record should be set for quality (Right click on speaker in your task bar, adjust audio properties.)