Windows 7 Microphone Random crackling

I have a Sennheiser headset that i use with skype. it worked fine until today when my voice randomly started crackling on the other end of the call. I tested it on my laptop and it worked fine with no crackling.

Back on my desktop, I then used my auido control panel to playback my mic through the speakers and it came out perfectly with no crackling.

Then I used the windows sound recorder to check it and i recorded myself talking and the crackling was there. so its only there with windows sound recorder and on my friends computer.

Any ideas would be helpful ?