A bad sector is any flaw or defect with the computer hard drive. When encountering bad sectors, it is a strong indication that the hard drive is failing or is already bad. Although disk drive utilities such as ScanDisk can mark bad sectors not to be used, consider replacing the drive and make a backup of all important files immediately.
Can I still use the drive?
Yes. A drive with one or more bad sectors can still be used, and when anything new is installed or created on the drive, any bad sector is skipped (if its been marked). However, any data that was in the bad sector is lost. If that bad sector was used by system files or operating system software, you may encounter system errors. Repairing this error may require a whole or partial reinstallation of your operating system.