Question Function Keys are not working in Sony Vaio Windows 8.1 Pro!!!

[TONSING]

Anyone using Sony Vaio 'Svf152C1WW' with running windows 8.1 pro?

The function keys are not working. I already installed the required drivers - Sony Parcer Extension Driver, Sony Shared library and Sony Vaio Event Service. Rebooted the windows in each steps.

Also, the Vaio Event service status is set to 'automatically start' in the services.msc console as well as in the 'startup menu' under msconfig. However, still all function keys are not working. I formatted the windows several times, and reinstall all the above said drivers. But still no success.

Anyone knows how to fix the issue?

 

[TONSING]

First of all Check your BIOS settings, Update your BIOS and Reinstall Your windows.

I already did reinstalling windows and its corresponding drivers several times. There are no options menu in the BIOS to enable or disable the function keys.

I also did the above said 3 required drivers installed for the function keys to work. However, still the keys are not working.