The icons are hidden when inactive. To change this rt.click the task bar; select properties; and uncheck the hide inactive icon box,this will unhide all of them. If you want to just change the one instead of unchecking the box, click the customize button, scroll down to the vol. icon and highlight it, in the drop down menu pick always show then click apply.
I have an AMD 1.6mhz, 512 DDram, NVidia GForce 2 MX 200, running WinXP Home Edition. Approximately 50% of the time I do a cold boot the volume control icon in the "system tray" (near the clock) will not appear. Why? and what can be done to force the icon to appear 100% of the time?