which drivers are for my Sony Vaio laptop?

ok so i've installed a new windows on my laptop and now I'm trying to find all the drivers.
My laptop is a white sony vaio with intel core i3, windows 7, radeon graphics card and model number on the back says VPCCA3S1E.

BUT when i go on he sony website and look for my laptop i find the following 6 models with a different extra letter after '/'
"VPCCA3S1E/D VPCCA3S1E/G VPCCA3S1E/L VPCCA3S1E/P VPCCA3S1E/R VPCCA3S1E/W"

So which one is it?? They all seem to have few different drivers.. I downloaded all the ones from the model ending with '/L' but it seems to be the wrong one as a lot of drivers and functions of my laptop still don't seem to be working, for example the FN key for brightness and also most importantly the graphics card driver don't seem to be right as even normal videos don't play very smooth.

What does the '/' stand for and how do i find out which model is mine? because at the back of my laptop there is no '/' and the extra letter

 

If you boot into the bios, it should show your exact model number (and serial number). Mine was a custom configure to order, but I found it was actually a "/J" in the bios.

 

thanks for you reply, I've just checked but all it says in front of system model is 'VPCCA3S1E'... someone mentioned to me that it stands for the colour of your laptop but I highly doubt it.

 

Any clues in the manuals for these models? Download them all and check for differences.

 

I searched everything i could, but no mention of a just a plain "VPCCA3S1E". as far as drivers, on a fresh install you have to install them in the correct order to get FN and other functions working correctly.

see what I posted here:

http://forum.notebookreview.com/sony/722842-vgn-z540-windows-7-clean-install-issues.html#post9252897