On Tuesday 08 April 2014 15:43:29 Alexandre wrote:
> Then, some laptops has a function keys, on the same keys as F1,
> F..., where you can press FN+ (the mute button) to turn on or off
> the sound. On some lappies, these keys are driven by the software
> (in linux), or on older lappies, it is directly controlled by the
> hardware, which is more multi-platform friendly. Also, does the
> laptop has a hardware volume control, probably on the side of it?

That was it.  Thank you so much Alexandre.  There was a small actual 
button, immediately below the touch-pad.  Daft place.  It can 
obviously be touched by mistake far too easily!  

I now know the model: Dell Inspiron 9300.

Thanks :-))

Lisi