How can I reset the microphone properties of the internal sound card?

[AC Question]

When my microphone is on to Skype, there is a reverb sound: the keyboard clicks really loudly if I type anything, my voice echoes, and even the T.V. is "picked up" and there is an echo. The sounds are so loud I have to turn down the amount of volume for the computer, and that affects the volume of my voice when my family is listening to be talk when we skype. I want to rest the microphone to the original settings.