a4tech office kbs-26 keyboard problem with the multim. keys

hi
i've just bought an a4tech office kbs-26 keyboard, and i have some problems with the multimedia keys (play, stop, ...) controlling the winamp, or anything else (like windows media player).
i have installed the driver...
do you have any ideas?
thanks.

hi
yes there is the default function (for example the "play" ), or i can assign a program to the play button. but there is no choice for witch program to unction the play button. while my friend has another a4tech keyboard, and if he presses the play button the winamp starts, and the music too. without any setting, just instlling the driver...
if i press the button on the bottom of the screen appears the icon of the button i pressed, so it functions, but i don't know why doesn't control the winamp...