My gateway laptop has a (fn) key in the bottom left. In order to use any of my function keys 1-12 as they're intended, I must first press and hold this button. How do I disable this, so that hitting f-5 on its own will refresh my browser, instead of turn off my screen? I\ve tried (fn)+F9, but it didn't work.

Please help... Can't find a 'padlock' key as otherwise suggested by another user on a similar question.