Typically whenever a Windows user opens up My Computer, the main installation drive is always assigned as drive C: and any other partitions or USB drives get assigned with a letter after that but none of them gets the letter A or B. This makes a lot of confusion to the users because seeing a drive assigned the letter A or B is something that’s not going to happen in their entire lifetime. Some people think that these letters have been popped out from the list for no reason but in the real world, they still exist but no one gets a chance to see them anymore.
> A and B Drives in Windows <
The drive letters A: and B: are specially reserved for Floppy Disk drives and that’s the reason why users can’t see them anymore and the system never assign those letters to any other storages or drives. Back in the days where the computers came to life, hard drives are much rarer and even if it exists, they are much more expensive than twice as much as a computer or even more. The hard drive was an optional feature for those computers and most of the times they just used floppy drives. Even in the first version of DOS which is the DOS 1.1, it only supports floppy drives.
After some more improvements, MS-DOS 2.0 came with the supports of hard drives but till the MS-DOS 4.0 floppy disks got much more priority than hard drives. If you insert 4 floppy drives and a single hard drive into your computer, all those floppy drives get assigned with the first four letters which are “A, B, C, D” and the hard drive gets a letter after that.
This theory changed after the release of 5.0, which gives a small change by reserving the letter C to the very first hard drives but still the A and B is going to be the floppy drives while any other additional drives get the letters after C. If you plug in a floppy drive to your Windows 10 system, it’s still going to get assigned the letter A. But this doesn’t mean you can’t change those letters manually and the users can assign the letters A and B into SSD, Hard Drive or any other storage they prefer.
Furthermore, it’s possible to change the main installation drive letter from C to whatever the users want but this has to deal with some advance windows registry files which means it has to be done with a piece of proper knowledge or else the whole system can be crashed itself.
Even though you changed the main installation drive letter to any other letter, there will be some issues with compatibility because most of the softwares are instructed to select C drive as the main drive and if you changed it into something else the softwares may confuse while installation progress occurring numerous issues in the system. For Linux or MAC OS users, there are no drive letters inside those operating systems.
__/–Brief Overview of Linux & MAC OS–\__
In Linux distributions, the highest possible directory is the root folder indicates by “/” and this equivalent to the My Computer view that contains and shows all the other stuff attached to the computer. But in the Linux root folder, it shows you the actual path unlikely in Windows. Within this root directory, there are a bunch of folders and each one of them can be an actual folder on the drive or a mount point that works like some sort of a shortcut or a virtual folder.
For all the other secondary drives you want to be plugged into the system has to mount with a pathname. There’s a special folder to mount the devices called “/mnt” that helps to keep things more organized wy rather than just mounting it to the root folder.
All these Linux things may be confusing if you are not familiar with them because Linux comes with its own file system. You can check the full overview of Linux OS from here for more in-depth details about the structure. In MAC-OS, there are no drive letters but it shows the drive name and if you use File Explorer you can get something that works as same as My Computer in Windows. Both MAC-OS and Linux are based on UNIX so in the backend, both these systems must have the same file structure inside.
This weird drive mounting system takes place in Windows systems as well but nobody wants to use them at all. Those people who wonder how these things work can also give it a try and it just a simple process. Just go to disk manager and right-click on the drive you want and click on “Change Drive Letter and Paths” in the dropdown menu. By there you can change the drive letter by clicking on “Change” or you can add a mount point by clicking on “Add” and selecting any empty folder.
By doing that the empty file works as a shortcut to the drive which you selected earlier. By using this method, users can plug in more drives as much as they want without limiting them to the 26 letters.
These are basics and some other side topics you need to know about drive letters in Windows PC, why there is no A: or B: drives and how other most common operating systems manage their files. Always remember not to change the C drive letter because by now it’s not just a letter but it’s a standard way of indicating the main installation drive that helps other software to carry on their tasks.