Hard Drive, clicking but not down and out!

My hard drive has been getting annoying and started this clicking noise, which freezes Windows or any program when loading it, normally, this would seem as a "Hard Drive Failing Sound" but I know for a fact it isn't since I tested the hard drive in another PC for a week, opening programs such as Photoshop CS3, defragging and Chkdsk.

Coincidentally, this all start three weeks back when I upgraded from my 64-bit to Dual Core, changing the Video Card, RAM, chip and motherboard.

Any ideas what the problem could be?

EDIT: If this dies, I won't be here for awhile. 

EDIT2: Sometimes my Hard Drive works perfectly for hours, then it starts to heat up pretty bad and click.

normally, this would seem as a "Hard Drive Failing Sound" but I know for a fact it isn't since I tested the hard drive in another PC for a week, opening programs such as Photoshop CS3, defragging and Chkdsk.

Because you don't want it to be bad, doesn't mean it won't be. You'll regret it really if you don't backup important stuff. If a drive decides it's getting corrupted sectors it'll just mark those sectors as bad and then not use them any more, appearing to your OS as if the drive is just fine. It'll function just fine as it's dying until it actually DOES die too.

Download SpeedFan or some other S.M.A.R.T. capable tool and have it check it;

I'm back, I found out the problem;

I put my SATA cable in a special slot, so the hard drive could not read or write, plus SF gave me an OK report.