Background information
Linux instead of Windows: SteamOS makes the Asus ROG Ally X faster and better
by Philipp Rüegg
Why C:? The story behind the Windows drive
21.4.2025
Translation: Katherine Martin
Pictures: Dayan Pfammatter
If you’ve ever worked with Windows, you’ll be familiar with C:, the default Windows drive. But why this prefix? What ever happened to the A: and B: drives?
If you have a Windows computer, you’ll have the C: drive. Basically, it’s the default drive on every Windows computer (linked article in German). In other words, it contains not only your programs and documents, but also your entire operating system and any other file on your computer.
Many people only have the C: drive on their Microsoft machine. However, if you have a second hard disk or CD drive (do those even still exist?), it’s a different story. In that case, you’ll also find the D: drive on your computer. A third hard disk would be named E:, and so on and so forth. Makes sense, right? A new letter is assigned for each new drive in alphabetical order.
But hang on a sec. If it’s all done in alphabetical order, where are the A: and B: drives? Did Microsoft somehow forget the alphabet? I mean, it’s literally right there in the names «Alpha» and «Beta». So where are A: and B: hidden?
First came the floppy disk
To figure out where A: and B: went, we need to do a little history lesson.
You see, Windows hasn’t always been installed on the C: drive by default. Back in the early 1980s, when Windows was still MS-DOS, floppy disks were used for installation instead of hard disks. At that time, HDDs were large, heavy and, above all, eye-wateringly expensive. What’s more, the rudimentary Microsoft OS was still small enough to easily fit onto a floppy disk. At that point in time, the system took up roughly one and a half megabytes of memory.
However, as early as 1988, Windows 2.0 was launched (website in German). This was the first version to require an HDD. Consequently, the C: hard disk drive was added alongside A: and B:. And the rest, as they say, is history.
A remnant of times gone by
Of course, operating systems aren’t installed on floppy disks any more. Windows 11 alone requires at least 64 GB of storage space – or 45,000 floppy disks. If you stacked that many disks on top of each other, you’d get a 150-metre high tower!
Even so, the A: and B: drives will probably remain dedicated to floppy disks forever more. After all, Windows is famous for hiding elements from the early days of computers deep within its operating system. Just think of the Device Manager, the Control Panel or – right on topic – Disk Management. All these elements still look the same in the current Windows 11 as they did in 2007.
If you really want to, you can give your default drive a name of your choice when you set up Windows. In theory, there’s nothing stopping you from setting up an A: drive on your computer as a tribute to the floppy disk.
Either way, we can count ourselves lucky that computers back in the day only had two floppy disk drives instead of three. Let’s face it, C: looks much happier than D:.
Header image: Dayan Pfammatter
Dayan Pfammatter
Freelance Editor
pf.dayan@gmail.comI've been fascinated by all things keys, displays and speakers for basically as long as I can remember. As a journalist specialising in technology and society, I strive to create order in the jungle of tech jargon and confusing spec sheets.
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