Microsoft XP OS. The headphones on the headset work but the mic doesn't, it used to before I started playing around with mp3 recorders, I must have messed something up. Under Control Panel->Sounds and Devices in the audio area I have as Sound Recording Default Device these options: Realtek HD input, Realtek Front Green Jack, Back Line in/Mic, Front Line In, and Realtek Front Pink Jack. Which one should I have as the default? Under Sound Playback I have the microphone mute(not that this makes any difference) Please help I really need to call back home. Also if I select Front Pink when I do the Test Hardware option under Voice, it works but when I try the sound recorder or Skype it doesn't. Thank you so much for your help.