Why C Drive is C Drive?

In computers, active storage drives are automatically assigned a drive letter, beginning with the letter A. The DOS operating system followed the drive letter with a colon, as in A: . Prior to flash memory devices, computers incorporated floppy disk drives for portable storage, so the A and B drive letters were preserved by the system to be assigned to these devices. This left C as the first letter available for the hard disk. So it is that the hard disk became known as the C: drive.

In days past hard disks were small enough that they were not divided into partitions, so a single drive letter was all that was required. The operating system was always installed on the C: drive and virtually all instructions for software and device drivers also referred to the C: drive. Today it’s a different story.