Digihumm

The number of hours of usage is usually specified by the manufacturer.  However this  does not take into consideration boot sector damage which would render the hard disk unusable.

• Older hard drives have a life span of  100,000 hours
• Newer hard drives -  200,000 hours
• SCSI drives (used in servers) -  300,000 hours

The lifespan of  a hard disk depends to a very large extent on the usage.  Most manufacturers define it in terms of the number of hours. So if you use it extensively, it will last for a shorter period.  On the other hand, if you leave it unused for long, the hard disk could get corrupted and important data may be wiped out.