You receive a notice, either from a drive utility, a SMART notification, or you are losing pieces of data. You may be beginning to get bad sectors on your drive. As opposed to repairs, the key to this problem is addressing it immediately.
The first think to do if you have reason to believe you are getting bad sectors? Back up your data now! All of it, whether you're sure or not, just start getting it copied. You can be sure of the problem later, now is the time to protect yourself
Once you've got everything you can get, there are a few different possible fixes for the situation:
Remap the bad sectors to remain unused in the future. Most drive manufacturers have drive utilities to do this, as does Windows. If bad sectors are cropping up, though, this is at best a stopgap. Bad sectors are a good sign that more bad is coming.
Fix problems that affect all drives in the system. These problems include BIOS issues, and occasionally drive cables that are too long. Check that your settings in the BIOS match those on the drive, and use as short a drive cable as is possible in your machine.
Fix problems of just one drive. These problems can occasionally include PIO settings that are set too high for your particular drive. It may also be worthwhile to check the manufacturer's website to see if there is an update firmware for the drive itself.
In all likelihood, you need a new drive. It is much more likely than not that if bad sectors begin cropping up on a formerly functioning drive, it is a sign of imminent failure. The importance of backing up immediately, as much as is possible as soon as the error is known, can not be overstated. We do not recommend continuing to use a drive, for example, after the bad sectors have been remapped, except to retrieve data.
We hope this helps you if you have this problem, let us know if it helps.