HOW 2 Adjust computer volume through slider control that pops up after hitting function and page up/down keys.

I used to adjust the volume of my laptop (Windows xp) using the funcion (FN) button and the page up/down key. Although it still adjusts the volume, it doesn't show the pop-up volume control slider. This showed wheather the volume was all the way down, or what level the volume it's on. I know i can double click on the volume control on the taskbar and get various adjustments, but I want the POP UP slider that automatically came up when I used the function and page up/down key. Any help?? Thanks..HOW 2 Adjust computer volume through slider control that pops up after hitting function and page up/down keys.
The only way to get the slider is to click on the loudspeaker icon on the task bar. Fn-PgUp/Down works at a different level in the O/S.