Just curious if there was a utility where it checks for errors on the hard drive? Recently, my macbook has been acting up; slow downs, and freezing. Why this happens? Not sure what so ever to be honest. What may cause this would most likely be an error, or errors that is within the hard drive. Also, just wondering if there was a defraging utility for the mac. If so, that would be great, my hard drive would most likely need a defraging.