TRY THIS LINK, it sounds a lot like your problem. Also try this extra link.
Okay, the diagram is part of an installation manual, with a picture of your computer sound jacks. You're supposed to have plugs which match in color, and then on your woofer you match the colors, too for speaker hookup. If you don't have those speakers and the woofer, the diagram is useless. The blue is for microphone, the green is line-out (so maybe use that one). The pink, I don't know.
Do you have any other audio source on your machine besides Realtek? Or do you have a webcam you can plug in and use? I ask, because I had the same problem in Win7 with my Dell machines (Alienware is part of Dell), except for the bad out jack: Realtek doesn't work well until there is another audio source. I found out that when I plugged in a Creative Soundblaster usb audiocard, suddenly there were two options and I finally got the Realtek Manager to configure in Personalize Sounds. So after that, I plugged in a Logitech webcam and removed the Creative, so there are always two audio sources. Now Realtek works.
But I still don't know if that will solve your speaker out problem. For that, I just used a audio splitter (sorry, I don't know its name in German).
Edited by brainout, 17 July 2015 - 01:35 PM.