I have a laptop that has literally two seconds of battery life, so it is plugged in all the time. Sometimes it gets unplugged, stays on for a second or so, and then shuts down. The hard drive makes an awful noise. If this happens enough, will the hard drive fail?
Yes. Sudden power failure will cause file corruption and physical damage to the hard drive when the system is not properly shut down.
If the hard drive is making bad noises, you need to BACK UP YOUR DATA NOW!