Final answer:
The technician should use the FORMAT command from the OS command line tools to delete all contents on a hard drive in a manner that makes data recovery difficult, thereby adhering to the company's policy for secure data disposal.
Step-by-step explanation:
The technician should use the FORMAT command to delete all contents on a hard drive before its disposal. The FORMAT command is an OS command line tool that prepares a hard drive for use by wiping all existing data, creating a new file system, and installing a fresh file system. It's important to note that simply deleting files or using the DEL command does not remove the data securely from the disk; it only removes references to the data. FORMAT, on the other hand, makes data recovery more difficult.
The CHKDSK command is used to check the integrity of the file system on a disk, and the SCANDISK command is a legacy tool similar to CHKDSK. Neither CHKDSK nor SCANDISK can be used to securely wipe a hard disk. When using FORMAT, the technician may also apply parameters to overwrite each sector of the drive, so as to ensure data cannot be easily recovered, thus meeting most company policies on data disposal.