driver for geforce 8400M GT driver works?

hi to all developers, i would like to begin to develop simple OpenCL applications ( i have to learn a lot …) so i decided to download the drivers reccomended for my video card. I have look on the nvidia pages and my card is supported ( i have an geforce 8400M GT on a sony vaio notebook) but when i execute the installation process i receive an error : not video car supported, i have downloaded the Green 280.26 driver (august, 9 2011) there is some solution for this problem? thanks