Disable a FN-key combination permanently?

Everytime I accidentally press FN+Left mouse, I enable tap-to-click (which I want to have off). I can disable the function with the same combination, but I'd like to find out a way to permantently disable tap-to-click. Is this possible?

I have Win 8 Pro now, but Vista and Win 7 behaved the same way, so I reckon it should be a Windows thing...

Doesn't work for me, so maybe not a windows thing.

laptop mice have the generic windows settings as well as settings by the maker; have you checked both?

My bad. It's not a laptop, it's a home built HTPC. The input device is a Logitech K400 wireless keyboard. The SetPoint software is set to "off" for tap-to-click, but this FN+Left mouse still activates/deactivates the tap function.

Of course it may be the actual keyboard that has this hardcoded, but shouldn't it be possible to somehow block this very function?