Each key can be mapped to a different action through the game keyboard settings. If you're having problems with a key working in a game, make sure the key is properly mapped.
It's not uncommon for a program or operating system to cause problems with a keyboard that prevents some of the keys from working. If the key works in other programs, then that key does not have any functionality in that specific program. Test the key that isn't working in more than one program, such as Notepad, a word processor, and your preferred Internet browser. Some keys, such as the function keys ( F1 through F12), do not work with every application. Some keys aren't used in certain programs If your keyboard has an LED indicator for the Num Lock key, the light should be turned on when the numbers can be typed. Num Lock is used to switch between the primary function (numbers) and secondary functions (arrow keys, Home, Delete, etc.) of the numeric keypad. If the keys on the number pad don't work or are behaving oddly (e.g., moving your cursor), press the Num Lock key.
Some keyboards may label the F-Lock key as the Fn key.