The hard drive is labeled the C: drive due to the history and evolution of computer storage systems. In the early days of personal computing, the first storage devices used were floppy disks. These disks were labeled using letters, starting with A: and B:. When hard drives were introduced, the next available letter, C:, was used. This convention stuck and became the standard labeling system for storage drives on personal computers.
The History of Floppy Disks
Floppy disks were introduced in the early 1970s as a storage medium for personal computers. Some of the earliest floppy disks that set letter drive naming conventions were used on the IBM 350 disk system in 1969. These disks were read-only 8-inch floppy disks. The first read-write floppy disk drive was introduced in 1971 by IBM. It was called the IBM 23FD and used 8-inch disks.
In the late 1970s, 5.25-inch floppy disks, dubbed “minifloppies,” started gaining popularity. These could store much more data than 8-inch disks and were smaller and more portable. The 5.25-inch disks became standard on early personal computers like the Apple II, Commodore PET, and Tandy TRS-80.
By the early 1980s, high density 5.25-inch disks could store up to 1.2MB of data. However, a new smaller floppy disk format was being developed. In 1982, Sony introduced the 3.5-inch disk, which could store 400KB of data. These disks were dubbed “microfloppies.” By the late 1980s, higher density 3.5-inch disks could store up to 1.44MB of data, making them more popular than 5.25-inch disks.
Floppy Disk Drive Letters
In those early days of personal computers, floppy disk drives were the primary storage devices. These drives were assigned drive letters starting with A:. The first floppy drive was labeled as A:, and a second floppy drive, if present, was labeled as B:. This established the convention of assigning drive letters sequentially to available disk drives in a computer.
The Introduction of Hard Disk Drives
Hard disk drives for personal computers first started appearing in the late 1970s and early 1980s. These early hard drives were bulky external devices that attached to a computer system via interface cables. Some of the first hard disk drives had storage capacities of 5-10MB.
By the mid-1980s, internal hard drives that could be installed inside a computer case became more common. The early popular personal computers that shipped with internal hard drives as a standard component included:
- Apple Macintosh (1984)
- Commodore Amiga (1985)
- Atari ST (1985)
- IBM PC/AT (1984)
When these internal hard drives were added to personal computer systems, the next available unused drive letter was assigned to them. Following the standard set by floppy drives, the hard drive was designated as the C: drive.
Why C: for Hard Drives?
The decision to label the first hard drive partition as C: has its origins in the IBM PC and the PC-DOS operating system. The IBM 5150 PC was released in 1981 with PC-DOS 1.0. This operating system supported two floppy drives labeled A: and B:, and the next available letter was C:. When the IBM PC/AT was released in 1984 with an internal hard drive as standard, this drive was labeled as C:.
Microsoft’s MS-DOS system was modeled after PC-DOS and also adopted the C: designation for hard drives. Since MS-DOS and PC-DOS became the dominant operating systems for PCs, the C: hard drive letter became entrenched. Competing operating systems like CP/M and later versions of Microsoft Windows also followed this same drive lettering scheme set by PC-DOS and MS-DOS.
Evolution of Hard Drive Capacity
While the C: designation has remained to this day, the capacity of hard drives has increased enormously over time:
| Year | Typical Hard Drive Capacity |
|---|---|
| 1980 | 5-10 MB |
| 1985 | 20 MB |
| 1990 | 40-80 MB |
| 1995 | 500 MB – 1 GB |
| 2000 | 10-20 GB |
| 2005 | 60-120 GB |
| 2010 | 500 GB – 1 TB |
| 2015 | 2-4 TB |
| 2020 | 8-16 TB |
Early hard drives held megabytes (MB) of data, while modern hard drives can store multiple terabytes (TB). This explosion in capacity has enabled users to store vast amounts of programs, documents, photos, videos, and other data.
Other Early Uses of Drive Letters
While floppy and hard drives were assigned letters first, other types of storage media also received drive letter designations in the early days of personal computing:
- Cassette tape drives – Used with some early computers like the Commodore 64, cassette tape drive was designated as device T:.
- RAM disks – Using a portion of RAM as a simulated disk, used for temporary storage. Often designated as drive X: or Y:.
- Optical discs – CD-ROM drives were widely used by the late 1980s, designated as drive letter D:. DVD drives later as E:.
- Zip drives – Removable Zip disks popular in the 90s, as drive F: or G:.
But the A: and B: for floppies and C: for hard drives proved to be the most persistent drive letter designations over time.
Why Has C: Stuck Around?
The C: hard disk drive letter has persisted for a number of reasons:
- Early market dominance of MS-DOS and PC-DOS cemented the C: hard drive convention.
- Backward compatibility in later versions of Windows supported keeping C: as the default for the boot hard drive partition.
- Many applications and utilities were hardcoded to use C: as the default drive letter.
- Administrators and developers were used to working with C: as the boot drive.
Back in the era of MS-DOS, having the boot hard drive as C: was a technical necessity. But modern versions of Windows can boot from any drive letter. The convention remains primarily for historical compatibility reasons.
Can You Change C: to Another Letter?
Because so much legacy software relies on the C: drive letter, changing it is generally not recommended. However, it is possible to do so in certain situations:
- If completely reinstalling Windows, you can choose to install it on a partition with a different drive letter.
- Using Disk Management or the DISKPART command, you can change the drive letters assigned to partitions.
- Some applications allow you to reassign the “system” drive letter they use after initial installation.
But tread carefully, as changing the main Windows boot partition from C: can cause compatibility issues with various applications. Most administrators stick with tradition and leave the primary hard disk as C:
Drive Letters Today
While floppy disks have disappeared and fixed hard disk drives are less common today, Drive letters are still commonly used in modern computers:
- Hard disk partitions – Main disk partition remains C:, additional partitions use D:, E:, etc.
- USB flash drives – Assigned next available drive letter when plugged in.
- Optical drives – CD/DVD/Blu-Ray discs use a drive letter.
- Network drives – Connected servers appear as local drive letter.
- RAM disks – Temporary storage using memory gets a drive letter.
So even though floppy disks are now obsolete, the drive lettering convention they initiated remains very much alive. The C: assigned to the first hard drive lives on as a remnant and reminder of those early days of personal computing.
Conclusion
In summary, the hard drive is designated as the C: drive due to historical conventions dating back to the earliest personal computers. The first floppy disk drives were labeled A: and B:, so the first hard drive was assigned the next letter, C:. This standard was established in the PC-DOS/MS-DOS era and continued in later Windows operating systems for compatibility reasons. It lives on mostly as a legacy practice, reminding us of how far storage technology has come since the days of floppy disks and small hard drives.
