'Fn' key make me type numbers

Hello,
the 'Fn' key make me type numbers and symbols instead of letters when I want to.
However, it looks as if the 'Fn' key was stucked.
I can't type the 'i', 'u', 'o', and 'p'. All I get are numbers and symbols.
How do you reset the 'Fn' key? I have tried restarting the laptop with no avail.
Actually is my wife's Gateway laptop.
Any suggestions?