If you ever wondered why there are different storage drives in your computer, especially the C and D drive, you are not alone. And it is a fair question since you only see the warning message of the disk getting full for the C drive.
So, in this article, we’ll explain what C and D drive is on your computer and what are their functionalities.
In short, the C drive is the default drive of your computer. It is where your OS and all installed programs reside by default. D drive on the other hand bears no significance. It is just like any other regular drive like E, F, G, etc.
for a more detailed comparison, continue reading below.

Table of Contents
C drive vs D drive
The difference between c drive and d drive is important to know. Below, we are going to describe in detail about them.
What is C Drive in the Computer and What is It For
You use the hard drive for storing data on the computer. When you have installed your operating system, you installed that on your hard drive. And to install your OS, you can use various bootable USB devices. You may have seen that, in your file explorer, there is one or more than one drive named as local disk C, local disk E etcetera. Local Disk C is your C drive which is a partition of your hard drive. But if your hard drive is not partitioned, then you will see that your full hard drive is the C drive.
C: drive is the first available drive letter for hard drives on IBM compatible computers which are generally known as PC. That means the computer which is running on a Microsoft Operating System such as Windows or MS-DOS. You can also increase drive size without data loss.
C drive is the first active primary partition of your hard drive. It is recognized by the system itself. Your operating system is installed on this drive. This drive has your computer’s boot sector and other vital information. That means, when the computer is powered up, all the necessary information is gained from this drive.
Not only the operating system but also most other software is installed on the C Drive. It is possible to install other software on other drives. As the C drive is your system drive, it is convenient for you to install other software on the C drive.
What is D Drive on Computer and What is It For
The D drive is generally the first drive after the primary C drive. The D drive is generally used by manufacturers as a recovery disk. That means the D partition is set up by the manufacturer if there occur serious problems in the system.
Actually, it is not the same in all cases. For example, every computer today has a hard drive and disk drives. Disk drives are CD-ROM, DVD drive etcetera. If this is the common configuration of your computer, then C: drive is assigned as the hard drive, and the D: drive is assigned to the disk drives. In the past, A: and B: drive letters were reserved for the Floppy drive. But today it is possible to assign A: or B: drive as other partition of the hard drive.
Does the Name of a Drive Define Its Functionalities?
It varies from computer to computer. In the computer which is running on Microsoft operating system has a hard drive which is the C: drive. C: drive is the first available drive letter for the hard drives. Generally, the computer assigns A: drive B: drive for the floppy disks. Sometimes, A: and B: drives are assigned to removable media like tape drives. If you install other drives or create a partition on the installed hard drive, they will be assigned the drive letter D, E, F, and so on.
Suppose your computer comes with a hard drive and a disk drive such as CD-ROM, or DVD drive. In this configuration, the C: drive will be the hard drive, and the D: drive will be your disk drive. Now the question should arise what about the A: and B: drive. Though no floppy disk is installed, as a convention, A: and B: drive letters to remain reserved for the floppy disk drive.
But today, this convention is not followed most of the time. For example, my computer is running on Windows 10, and I have two partitions on my hard drive. The system drive of my computer is the C: drive and the other driver is my A: drive. Though I have no floppy disk installed on my computer.

Frequently Asked Questions
1. What is C drive and what’s the use of it?
Ans: C drive is the first available drive letter for hard drives on IBM compatible computers. C drive is the first active primary partition of your hard drive.
2. What is D drive and what’s the use of it?
Ans: The D drive is generally the first drive after the primary C drive.
3. Why is C drive called the system partition?
Ans: It is called the System partition because your operating system is installed on that drive and this drive is recognizable by the system.
4. “C drive is full” warning is given to me. What should I do?
Ans: You can do several things for that matter. Follow the section named “How to solve “C Drive is full” issue in Windows” in this article. You will find the answer there.|
5. Can I use my D drive instead of C drive?
Ans: Yes. But it is recommended to install the operating system and other software on the C drive and store files and other folders on the other drives.
Summing Up
Being a PC user, partitions are found on the hard drive. Sometimes, you may have to spend some time to solve the problems that are caused by the partition system. Now you know all about C drive and D drive and their uses. If you find that your C drive is full you now know what to do. If you have gone through the whole article, you know all the answers to your questions on C drive and D drive and partition system on the hard drive.
Great! Good to see this post. I appreciate the tips you shared. Thank you!
You are welcome!
How do I open the D drive?
Double click on it and you will be able to open the D drive, thank you!
I cannot get my D/drive to operate properly
If you are facing issues then you should check for issues with your D drive. Find the issue and solve as soon as you can, otherwise, the disk will be damaged and you will lost your data.
DO that mean we can lose our data if sored in drive d?
so which is the better option to store the data to keep it more safe?
If you want to store your data keep and secure then you will need to store them in D drive. C drive is for the Windows files and whenever you will reinstall Windows, you will need to clear C drive totally. That’s why, you should keep them in D drive