Audio Systems: 1/8 stereo plug to bare wire, music playback, panasonic model

Question
I've got a Dell Inspiron 560 computer that has auxillary 1/8" jacks for "surround sound" speakers.  I got Panasonic Model No.: SB-PS725 speakers and can not get them to work.  I went to Radio Shack and purchased the Goldseries 1/8" stereo plug, soldered the speaker wire to the plug and got nothing at all.  I tried all of the speaker/headphone jacks on the computer and still nothing.  

All I'm trying to do is run speaker wire outside so I can listen to my "iTunes" on the computer when I'm in the back and/or front yards.

Thanks

Answer
More than likely, those outputs require powered speakers. Also, outputs labeled " surround" are not going to carry the same audio as the main L&R outputs. Surround audio information is encoded differently, and those channels are probably not being used in iTunes for music playback.