Microphone Issues

[Nerwin]

alright guys, This is really making me mad... I have gotten my mic work the way i want before, Like it works fine and you don't hear the loud high pitch noise when you turn it up, I could have my Mic on all the time and have my speaks full blast and I don't here a thing from it, But if i'm talking to my friend, I hear him perfect and for some reason now, it wont let me do that, It works but all i hear is this high pitched noise that sounds like a interference but its not, I done it before fine. I am hoping someone here knows how to do this, I use to know but I must of forgot.

Thanks.