Question : Problem: Function Key not work!

I have the two sony notebooks
sony vaio VGN-T37GP and sony vaio VGN-T50B. The function keys cannot work so that cannot I cannot change the volume and brightness of the notebooks. How I can fixed it??

need driver download? please give me the link! Thanks!

Answer : Problem: Function Key not work!

how did you find it? with an external keyboard?
then in device manager delete the keyboard, or upgrade the drivers.