Looking for some help, *mic* issues.

I have been using an old mic since some time. It started having some problems in game. My voice was too high and there were some annoying stuff in it. I couldn't make the volume lower for some reasons ( in all mp games ). I mean i could but still was too high and annoying. I didn't make anything else since i thought it was because the mic was too old. Now i have a new one just for gaming. It's very cool but it's having the same problem as my old one. Can't make the volume lower and still a bit annoying while i use it. Now it's probably a problem from my pc, that's for sure but i don't know which.
Any suggestion that might have coused this?
Thanks in advance!