Lock touchpad key Fn+F6 not working in my laptop

I pressed FN+F6 key but touchpad is not disabled!!!!

Fn+F6 on\off touchpad is not working!!! Please help me!!!

For solve this problem read following tips:

1. Installing the OSD utility driver from original DVD driver pack of your laptop.

2. If the Fn+F6 keys still do not work go to http://www.synaptics.com/resources/drivers and download your required driver platform(I've used the Windows 8/7/XP/Vista 64/32-bit Edition v16.3.15.1 for Windows 7 and it solved my problem).