All too often, hard drives fail with no warning whatsoever. One minute the computer is working fine, the next you have a "blue screen of death" and all your data is gone. So, what's the lesson here? Don't rely on warning signs to predict hard drive failure. Assume that your hard drive is going to fail, and back up critical files. If you have a reliable back-up, you'll save yourself many headaches.
Some mechanical components can fail gradually, however, so occasionally you'll know when a drive failure is imminent. These warnings fall into two categories: sounds and performance problems.
If you spend a lot of time sitting near your computer, you're probably familiar with the usual sounds it makes. If you hear the hard drive making any unusual noises, that's probably a clue that something is going wrong. Grinding or screeching noises might mean the bearings or spindle motor are failing. A clicking, clunking or clanging sound could be the read/write arm slamming back and forth. Sometimes these sounds can be subtle and difficult to detect. If you think you're hearing funny noises, open your computer's case and listen with your ear close to the hard drive while someone else uses the computer to save or move some files.
Performance problems include a sudden increase in the frequency of freeze-ups and crashes. Of course, these types of performance problems can be symptomatic of any number of computer maladies, from viruses to memory leaks to non-drive related hardware failures. A more specific tell-tale: saving or moving files suddenly takes a very, very long time. When you run into any of these symptoms, back up anything that isn't already saved and hope the drive lasts long enough to get everything you need copied to another disk.
Next, we'll troubleshoot your dead drive.