ASUSFn key is always on. How to turn it off?

Dec 23, 2018
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Hi, I'm using ASUS N43SL laptop (Windows 10).
Currently, I can control the volume by just pressing F11 / F12 (no need Fn).
And, the "c", "v", & "spacebar" are not working.
Plus, the arrow keys only can be used for media playing.
I wish to get back the default setting.

Below are the steps that I'd tried, but to no avail:
1) Fn + Esc
2) Fn + Num Lock
3) Goto Device Manager > Uninstall keyboard & Restart
4) Goto Control Panel > Uninstall Touchpad & ATK Package > Restart > Install downloaded ASUS Touchpad & ATK Package

Thank you.