If the function keys, such as the LCD brightness or volume control, do not work, install the following drivers and software in the specified order:
•Download and install the drivers and software available online through the Downloads tab section of your support model page.
•It is recommended that while you are at the Drivers & Software page, to make sure that your computer is as up-to-date as possible, you download and install all available driver and software updates.
•You also may use the VAIO Recovery software to install the drivers and software. For information about using the VAIO Recovery software refer to the operating instructions supplied with the product. Manuals are available online through the Manuals tab section of your support model page.
3.Sony® Shared Library
4.Sony Firmware Extension Parser driver
5.Sony Notebook Utilities