Screen indicators vanished after Windows reinstallation

Although I reinstalled Windows XP from the CD that my Inspiron 9300 asked me to make when I first purchased it (and then loaded all the updates suggested by Microsoft), the on screen indicators showing some functions like CRT/LCD changes, brightness change, volume change, battery (and generally the Fn+ something keys) don't appear any more.

Does anyone know how I could have these again?

Also, is there a way to bring back some of the (basic) software that was preinstalled?

Thanks.