VAIO VGN-SZ4XN/C Function Keys Not Working

[nektar]

After downgrade from vista to xp the and intall all the drivers,when i push function key and sound or brightness not working.What i did wrong???

[Blencogo]

Hi nektar and welcome to Club Vaio.

Have you installed all the XP Utilities for your model?

You need to install these in order starting with :

Sony Utils DLL
Sony Shared Library
Vaio Event Service
Setting Utility Series