Monaural Rather Than True Stereo?

Will try to describe my problem as best I can.I have a 3 yr old Desktop HP PC.If I remember right, it came with "integrated audio," but I might be wrong with this.Have the Creative SoundBlaster audio setup/program too.Just bought a new pair of Logitech desktop speakers.Not too expensive; only about $ 25 or so.Nice sound, but:If I do the speaker test that is on one of their menus (the Creative menu), and click the left speaker, sound comes out of both speakers. Same if I click the right speaker; sound again comes out of both. Now that I am aware of it, DVD's and other sounds also seem monaural from both speakers; each speaker playing the same thing.There are all sorts of options, but I can find none that say "Balance" as I would expect. Also, no balance knob on speakers.

It seems as if the system is working in a monaural mode, rather than stereo.All the cables, etc are stereo, and I am feeding them into the green Line-In jack on the back of the PC.how to change it from, apparently, Monaural to true Stereo. I looked in Device Manager settings for sound, and everywhere else that has a sound option screen, but nothing seems appropriate, or works.I dumped the old speakers, so have no idea if the same with them, or a problem with these new Logitech ones. My "guess" is that the old ones probably played the same way, and my problem is with some setting in ther PC rather than the new speakers, but...?