Hello, yeah, had that happen to me before. Try this, with the speakers unplugged , restart computer, when it has got everything started , as far as start up processes finished, plug in the speakers, You should see the Balloon pop up of New Hardware installed, and it should auto detect it and after a few seconds or so, it should show you in the Audio Manager , when you open it up, a Sound Manager option, test it out and see if it giving you the stereo sound by pressing the test button , which is in the Speaker tab, you should see a blue test button.. check that out and post back how that works out please.
This icon i have on my taskbar is a red icon of a speaker. see if you have that , and open it up to do what i have posted above ^^^^^.