If a key is physically stuck in the down position, you might not have to replace the keyboard. Most keys can be easily removed by inserting a butter knife under the key and prying up. After the key has been removed, using a swab with alcohol, clean the underside of the key and the key's slot in the keyboard. Replace the key by snapping it back into place.
Other tips to think about when encountering a stuck key:
Turn off the computer before working on the keyboard.
If the keyboard is still under warranty and the key is stuck, you might want to contact HP to see if the keyboard can be replaced before removing a key. If the key is stuck due to liquid or other substance getting into the keyboard, cleaning might be the only option.
Longer keys such as the Space and Return probably have a small metal rod for support. This rod must be inserted into the key and keyboard before replacing the key into the keyboard.
Keys on thin wireless keyboards, such as those used by HP TouchSmart IQ Series PCs can be more difficult to replace. Think about replacing the keyboard for these types of keyboards.
Figure : Removing and cleaning a stuck key