Microphone problem with Realtek HD

Hi everyone,
until now, I have been using USB Headphones with mic Genius HS-03U and everything worked just fine. But yesterday, I dropped them on the floor and the mic isn't working anymore. So I took my old head phones (pink in, green out) and wanted to use those. So I plugged them in, started to speak on skype and everything is fine again. But I use skype to communicate while playing games mostly and when I try to speak while im in game, the friend on skype can't hear me or it is really bad - he can hear few words, or not even that. if I speak in Windows, even when the game is started, it's alright, if I just stand in the game and don't move at all, it works fine, but as soon as I start moving or do anything in game, the problem starts... When I had the USB headphones, everything was fine. I have Realtek HD, MSI GX700, Windows XP. I have tried countless versions of drivers. None of them fixed this. Sorry for English mistakes.
Thank you for replying