Q. I’ve started getting strange messages when I boot up my computer. They say something about S.M.A.R.T. and say that the hard drive is going to fail. But Windows starts normally without any trouble. Do these messages really mean anything, or can I just ignore them?

A. Uh, oh. It sounds like you’re in for trouble. Definitely take this message seriously. The fact that Windows is able to start doesn’t make the situation any less serious.

S.M.A.R.T. stands for Self-Monitoring Analysis and Reporting Technology. It is a set of tools built into hard drives.

Sensors monitor various aspects of the hard drive’s performance. For example, the temperature, head flying height and spin-up time can be measured. These are some of the things that are usually monitored.

Now, the hard drive is not responsible for sending the alerts. The drive simply makes the data available. You need software that can make use of the data.

There are programs that you can use to access S.M.A.R.T. data. HDD Health and HD Tune are two free ones.

Also, some motherboards include tools that check the data when your computer starts. This is why you are receiving the notifications.

S.M.A.R.T. is a valuable tool. It gives you advance notice of hardware failure. So you can take steps to move data off the drive and replace it.

S.M.A.R.T. does have its critics. And, to be fair, it isn't failsafe. First, there are two types of hard drive failure: predictable and non-predictable.

Predictable failure happens gradually over time. There are usually signs that can be detected. For example, if the head flying height begins to drop, this portends a head crash.

As you can guess, non-predictable hard drive failures give no warning signs. For example, a chip on the hard drive could burn out.

S.M.A.R.T. will help with predictable failures. But it can’t help with non-predictable ones.

There is no industry-wide standard for S.M.A.R.T. There are many different components that can be monitored.

Manufacturers may monitor different ones. Or, maybe they'll monitor only one. When you buy a hard drive with S.M.A.R.T., you’re not really sure what you’re getting.

So, don’t rely on S.M.A.R.T. to save you from losing data. Back up your data regularly.

But when you start getting S.M.A.R.T. notifications, take notice. The drive could fail at any time. Stop using it and get a new drive.