FN keys don't work on Sony VAIO VGN-SZ18GP

The solution is as follows, which worked for me:

- Install Windows 7
- let it update all the drivers that it needs to
- Install additional Sony drivers that you need (XP drivers work just fine, but make sure to install them in Administrator mode, so, Run as Administrator), such as camera, fingerprint scanner, etc
- Install the Notebook Control Device Driver (without this the other software does nothing)
- Sony Utilities DLL
- Sony Shared Library

* restart computer *

- Sony Video Shared Library
- SUS (Setting Utility Series)

* restart computer *

- VES (VAIO Event Service)

After this one the Fn keys will start to work. The S1 and S2 keys don't work due to something to do with UAC (but I don't need them anyway)

- VAIO Control Centre (will allow you to change what the S1 and S2 keys do, even though you can't use them :) )

That's it and it worked for me.

Since they have no intrinsic meaning to Windows, those function keys require drivers from the laptop manufacturer to work. Unless Sony offers drivers for W7 you may be out of luck. You can try installing the XP drivers and see if they will work with W7. The Sony download page is here. I think the "Notebook Control Device Driver" is probably the one you need.