How can you tell if a hard drive is failing?
 

Is there some software you can run to check the health of your hard drive?

when it starts making a clicking noise on bootup is a good indication

it stops working???

The last one I had fail, started making noise. Hard Drive + Noise = BAD!

are you serious? my laptop is old and probably due to die soon, and it sometimes makes clicking noises :Oh crap

Windows or Linux?

The truth!

There are software utilities for checking if a drive is failing.

SpinRite

http://en.wikipedia.org/wiki/SpinRite

http://www.almico.com/speedfan.php - i like speedfan, it has a tab for s.m.a.r.t. readings and an online in-depth analysis

if it starts developing bad sectors, thats a pretty good indication also :)

well some times when you get the strange clicks noise its just indicates that you have some data fucked up on your hard drive to fix this you should go and run windows scan disk on your hard drive and the problem will be solved.

you can also check the event viewer at the system tab. Search for errors marked with a red x. If your hard drive has problems it should be tracked down there by the operating system with some relevant information regarding the problem such as "can't write or read from disk" etc..:pimp

Take it out and shake it. Shake it hard if you hear a rattle then it probably wasn't bad until you shook it to hard.