You could try calling Gateway and asking them about your keyboard. a year seems a bit soon to be having that type of problem with a keyboard, though they might try to claim abnormal use they might just offer to replace it free for the goodwill factor. replacing the keyboard on a laptop is not a simple thing as it involves opening the case and disconnecting and reconnecting some wires. this should be done in a shop to prevent the danger of a static charge frying your motherboard.

I would recommend that you check with local geeks about this. They would probably be willing to do it for a nominal fee.