A question was asked for almost exactly the same problem on Vista (astonishingly almost 8 years ago to the day) here, and I'm hoping an easy solution will have appeared in that time (and 3 operating systems later!)
Due to a recent desk rearrangement, my speakers are now on the wrong side (left playing right audio and vice versa) and spacial constraints mean that I can't switch them around. Is there any way to change which channels they use without installing additional software or buying hardware?
