Keyboard problem

Last month a few crumbs got into some keys so i took them off and cleaned them. All of them worked apart from the key in between 'h' and 'k'. It doesn't work at all but when i first turn the computer on and click on my account to type my password it in it seems as though theres a key stuck because it inputs a letter continuously until i press backspace. I'm certain its the key that broken because i took the key of again the other day and when i hit a certain spot it types it continuously so i dont think its completely broken. I'm wondering if theres some way i can reset the keyboard or is it something completely different. Any advice would be helpful.
Thanks,
Matt