Why "C" is the Default Drive Letter?

Why is "C" the default Hard Drive Letter in so many Computers?

Let us understand this fact in an simplest way,

If you are using a windows computer or a windows operating system,then head to the My Computer section by double clicking the My Computer icon from the desktop.

A windows which looks like in the following image will appear :-

Here, in the above image we can see The Drives in our computer and its size,we can also see the Drive letters assigned separately to each drive which is different from each one.

Here the drives shown are C,E,G,and I. 

where the C drive contains all the files related to operating system or application software's installed or saved.

Why is that? Why is ‘C’ the default drive letter – rather than ‘A’, which would make more sense intuitively – on so many computers? As it turns out, there is an interesting reason behind this C domination…

About History-

You might be a bit surprised to know that the hard disk drives, which are installed inside computers these days, and act as the basic storage units.Although hard disks have been around since the 1950's, they were not a standard/essential part of the computer system due to their high cost.

Floppy Disks-

Most standard floppy disks (like 5 1/4″, 3 ½” variants) could not store more than 1 MB’s worth of data.Therefore, it’s not surprising how quickly floppy disks were replaced by compact discs, and eventually became completely obsolete,If you were using floppy disks instead of a disc, it would take no less than 3,711 floppy disks to install Windows 8.1 on your computer!

Now coming back to our topic-

The floppy disk drives in computers using MS-DOS or certain other operating systems were labelled as ‘A’. After that eventually certain technological improvements were made and the new systems came with two such floppy disk drives, providing even more storage capacity.

This new drive was labelled as "B". No other disks were added ,so these two disks were labelled as "A" & "B" for floppy disk drives.

How Hard Disks evolved?

during that time when hard disk drives were evolved, they were far too expensive to be added to every computer.

hard disk drives grew more affordable and became a standard component in most computers by the late 1980s. Now, these new systems consisted of both floppy disk drives (A and B), as well as a hard disk drive. Labeling this new member as ‘C’ was the logical thing to do. 

Hence time went on,many new advancements came to existence and slowly The use of Floppy Disks came to an End. 

Floppy disk drives were entirely removed from computers, but somehow the label ‘C’ stuck with hard disk drives.

In fact, most Windows computers come with the first partition labelled as ‘Local Disk C:’ for that same reason. Of course, these labels are not set in stone. You can easily change them with a few clicks on your computer, provided you’re using an Administrator account. 

But many people ignore doing that.