Best sign that your hard drive is dying? Typically, noise, a lot of noise, specifically, grinding or a high pitched screech. Both are definite signs that your drive is starting to fail. Realize that ALL hard drives fail eventually, it's just a matter of time. What to do? Well if preserving your data is important do this.
First, shut off the PC. Until everything is fixed, you want that drive spinning as little as possible. Preferably, not at all.
You'll have to buy a new hard drive, of course, and install it. That's the easy part. If you want great performance from the new drive, get an SSD drive. The hard part will be recovering everything from the old drive.
If you have a complete, up-to-date backup, or you use a cloud-based backup service, congratulations. Your good habits are about to be rewarded. Exactly how well rewarded depends on what type of backup you have.
If you have an image backup of your C: drive, you can restore that to the new drive and be up and working almost immediately. Whatever program you used to create the image should have a way for you to boot the computer and restore it.
If you backed up your data files separately, you'll have to restore those separately, as well.
But what if you have your documents and other data files safely backed up, but never bothered to back up Windows itself? (As far as I know, an image is the only reliable way to back up Windows.) In that case, contact the computer manufacturer and find out how you can restore Windows to the new drive. Once that’s done, you’ll have to restore your programs.
What if you didn’t back up? When preparing this article, I seriously considered giving instructions for cloning the dying drive to the new one. But the more I thought about it, the more I realized that for anyone except a very skilled professional, that's a very bad idea. Cloning is generally pretty simple, but not when you've never done it before and your drive could die at any moment.
Instead, I recommend you contact a data recovery service. These services are expensive, especially for a noisy drive. But that's the price of not backing up. So, PLEASE, back up your drive now, while it is still healthy and simple to do. The longer you wait, the more pain there is.
The best-known services are DriveSavers and Kroll OnTrack. PCWorld editors have visited DriveSavers and been impressed with that operation, but Kroll OnTrack and other companies, such as Flashback Data, may be just as good. Data recovery isn't cheap, though, which is why a good personal backup routine remains your best option.