You can hear everything fine, as in when you talk into the microphone you hear it through your speakers?
If this is the case, you might have a different section of your sound control muted while the mic is working. There are a couple input controls that all in one way or another can mute your mic. You've got your master control, recording volume, line volume, microphone volume with Windows and some mics and sound cards have their own third party software that can work on top of your Windows Controller.
In Ventrilo, on the right side, click your setup button, and then on the window that pops up, go to the lower right corner and hit the Recording (Input) button. This should take you to your Windows recording controls. Once their, go to the Options pull down menu and select properties. In the bottom box, make sure that all the check boxes are checked, so you can see the full range of your controls, then hit ok. Check to make sure nothing is muted and that the slider bars are not on the bottom.
If that doesn't work, back in Ventrilo setup, you have a Hardware Input Mixer (Optional). This should allow you to set an override controller for your input device (mic). You should be able to set your sound card Input as the mixer device, select an mux and line, then use the Line Volume slider bar to set your level.
You can hear everything fine, as in when you talk into the microphone you hear it through your speakers?
if that first sentance is not true, get a new mic
