Why is the hard disk drive the C: drive?

Question

Why is the hard disk drive the C: drive?

Answer

On IBM compatible computers running a Microsoft operating systemsuch as Windows or MS-DOS, the default hard disk drive is the C: drive because it is the first available drive letter for hard disk drives. The computer assigns the A: and B: drives to floppy disks and sometimes other removable media such as tape drives. As you install other hard disk drives, create new partitions, and add other drives such as CD-ROM or DVD drives, they will be assigned to other drive letters after C, such as D, E, F, G, etc.
For example, most computers today come with a floppy disk drive, hard disk drive, and CD-ROM drive or CD-R / DVD drive. With this commonconfiguration, your floppy disk drive would be assigned to the A: drive, your hard disk drive would be assigned to the C: drive, and your CD or DVD drive would be assigned to the D: drive.