[alexadams77]

First off, what program are you using to play the CD's/music through? I'm not a computer genius, and some of these may sound stupid, but worth a check;

1. The 3.5mm plug from PC sound card is plugged into "Audio Out"
2. Make sure that you have "Front/Main Speakers" selected for PC speaker config, it almost sounds like you are using it as a "Center Channel" selection.
3. Cycle through the different PC speaker configurations (ie: stereo/4/5/6/7.1) and see if any of them work.
4. Check the volume Balance on both the main speaker setting and the program used to run the CD or music.
5. Try plugging the 3.5mm RCA into the "Main/Front" speaker slot where your computer speakers are plugged into, it could be just a bad input.
6. Reboot your computer and try again.