1. In the old times, no type of storage device is used in the computer, that is, no type of data can be saved in the computer of that time, at that time if you had to run the computer, you would have to use floppy. Disk had to be used, without a floppy disk the computer could not run, so at that time the first storage device of the computer was the floppy disk, which was named A.
2. After this there was development in technology and a new floppy disk was created, which was named B (B) drive, two different drives were made to run these two floppy disks, they were named A and B
3. A(A) and B(B) drives were already reserved for floppy disks in the system, so C was assigned to hard drives or hard disks, hence whatever windows were installed in the computer. It is always installed in the C drive itself, so at this time the name of the first drive of the computer is C.