Volume icon not working

I have a brand new Acer Aspire V3-572G. Its been a bit of a lemon so far, but I will give it the benefit of the doubt for just a while longer as I'm not particularly tech-savvy so perhaps the problem is me. Yesterday the volume icon (on the bar at the bottom of the screen) stopped working altogether. I can press it with the curser and it changes colour in the way it should when you click on something ... BUT nothing comes up ... no sound/volume control thing that I can adjust. I know I can use the Function key and arrows, but that is just fiddly, and for a brand new computer, I expect things to work. Can anyone help me with this problem? Is it me, or the computer? TIA