Call Dell with the error; they'll ship you a replacement drive (you can request that it be pre-imaged with the software and operating system) and replace the drive. Purchase a second SATA cable and then attach the failing drive as a secondary and see what you can read.

If you can read your data, you're all set; if not, you'll have to decide whether to purchase a data recovery service - they can almost certainly get your data back but such services are not cheap.

Like anything electromechanical, a hard drive can fail for any one of a host of reasons at any time. Could be a manufacturing defect, could be the drive was dropped somewhere along the line - you'll never know.