1. A computer-implemented method comprising: storing a data erasure program in a disk drive of a computer system; changing a booting parameter of a host operating system of the computer system to the data erasure program; rebooting the computer system after storing the data erasure program in the disk drive of the computer system; loading the host operating system of the computer system after rebooting the computer system; launching the data erasure program from the disk drive of the computer system after loading the host operating system of the compute system but prior to executing a file system check routine of the host operating system, wherein a system disk of the computer system is erasable before the file system check routine of the host operating system is executed and is protected from being erased after the file system check routine of the host operating system is executed; and erasing the disk drive of the computer system including the system disk of the computer system that stores the host operating system by overwriting data written on the disk drive with a pattern of data.