If your pc is installed with the touch-pad driver, then you will(usually) have an icon in the system tray to manage touch-pad.
Check for the touch-pad driver icon in the system tray(My laptop is installed with synaptics touch-pad driver,so in my system tray I have an icon for synaptics pointing device).
If it is there, click on it and you can see various controls to manage it.Look for the option to enable/disable it.
If it's not there then go to control panel search for Device Manager ,open device manager check for your touchpad device(will be under Mice and other Pointing Devices) Disable it.
And if you want to get back the Fn/F6 functionality to disable the touch,try reinstalling the touchpad driver.