Problems with my audio.

Hello. I have a problem with my sound. Since I am not an expert, I don't know what this could be. As you know, on the back panel on the green jack you can connect 2 front speakers or a headphone. When I connect my headset the sound is not synchronized and I hear it with distortion when I select "Headphone" on realtek hd audio manager on the back panel on the green jack and same happens when I connect the 2 speakers. By the way, my soundcard is Realtek HD Audio(ALC888) and is on-board. I never had a single problem with my speakers or my headset since I bought them. I think it is because of the drivers. My copy of windows is full. I don't want to select 2 front speakers on the realtek hd audio manager controls when I use the headset, because it has different features(for e.g. the 2 speakers have the virtual surround and the headphone has the headphone virtualization technology). When I connect them to the front panel I don't hear any distortion, the sound is perfectly well but I don't want them on the front panel because I have a problem when I speak with my friends on skype. I hear the music of my friend's computer when he listens to. Obviously I though it's because of his computer but it was not. When I plugged my headset to the back panel on the green and pink jacks I didn't hear anything of the sound played on my friend's computer. If you can help me with this I would be greatly appreciating. Good-bye and have a nice day ! P. S. Sorry for my bad english.