Try turning your computer off and back on.Hi Chineapplepunk! How are you?

Anyway, if there's a small space under the key, try twirling the corner of a tissue and cleaning it out. If there's something stuck under there, it might be the cause of your problem. Or try pressing it at different points, or using different pressures. Kinda like the advice they gave me when I asked how to pleasure a... nevermind... What I was saying was, yeah, keep trying to make it work. Also be sure it's the key that's not working. Sometimes you press something like numlock or whatever, and it messes stuff up. Try pressing all those buttons up top, near the screen of the laptop. Also, how old is the laptop? It is possible that it simply went kaput.
I hope this helps!