hard drive failing?

Occasionally my pc doesn't boot up, freezing before the windows login, and when this happens i hear a clicking noise, almost certain its coming from the hard drive. Strangely it seems to come and go, but do you think to be on the safe side i should just buy a new hard drive?

You can probably take the side off the case to be sure it is the hard drive that's clicking but once that starts there's not much use left. Right now I believe TigerDirect had a 1TB Seagate for $59 - as opposed to $149 or so due to circumstances outside the control of Tiger or Newegg. There's also a 1.5TB for $79. At least those are the prices unless you wanted an SSD.