I have a Sony Vaio VGN series Laptop. Originally shipped with Windows 7 x64 Home Edition(OEM). It had Fn keys combination to control volume and brightness. A nice overlay would show up on the screen to show current levels
Fn + F3: Volume Down
Fn + F4: Volume Up
Fn + F5: Brightness Down
Fn + F6: Brightness Up
Few months back, after a HDD failure I had to install Windows 7 professional(Retail). Now, even after installing all the Sony Vaio drivers, the brightness control is totally disabled. Volume control works but without any onscreen overlay.
Latest Update: Recently I Purchased windows 8. Now the volume control has a different overlay(on the top left part) but brightness control is still not working.
Any Ideas on how to fix this?