When I had my Dell computer, I had a 20 GB Western Digital hard drive in there. (I think Dell uses WD drives.) Anyway, about two years after owning my computer, I started to notice the occassional clicking. Over the next few weeks, the clicking started getting louder and more frequent. Then, one day, it just started clicking like crazy and it locked up my system. When I rebooted my computer, I got the nasty message that nobody likes to see....... "Can't find Operating System." 🙁 I panicked, called up Dell and they said that they'd send me a replacement. They just needed my credit card number so that they could cross ship my new drive. (Since during my call to Dell, I was able to get my system up and running.) But the clicking just kept getting worse and worse. Finally, the replacement arrived and I used Drive Copy to make an exact copy of the data on my dying hard drive. After making the copy, I tried to run scandisk on the dying drive and it could never complete. There were literally thousands upon thousands of bad sectors. Apparantly the clicking was the drive head banging against the platters of the hard drive. After that one experience, I'll never use a WD hard drive again. (That and the fact that I've read about a LOT of problems with WD drives and the "click of death.")
In my new system, I have a 40 GB, 7200 rpm Seagate Barracuda IV and I love it. It is fairly fast, and dead silent. Plus, I have not read nearly as many click-of-death stories about Seagate as I have about WD.