if it is cordless try a new battery.
You can also click on the start button lower left
Open the control panel
Look around at the list and open keyboard
See if there are any options there that might cure the problem.
If it is just the enter key giving problems it probably has a cracker crumb under it
Or gotten some sticky drink on it. Just pry it off (turn off the computer) and clean there.
I blow my keyboard out about once a week because we live in a very dusty environment.
Good luck