In professional data recovery, the steps taken when a hard drive is first received for evaluation are critical. These steps are built on both experience and knowledge. For example: If a hard drive has been dropped and therefore more than likely has read-write head failure, we would initially open the drive up in the cleanroom and check for damage to the read-write heads. If the drive goes to a location without a cleanroom, the only option they have to ‘test’ the drive is to power it up, risking further damage to the drive and possibly making the drive unrecoverable.