Home » Computer Guides » Computer Tech Guides » What Is A Hard Drive Partition?

What Is A Hard Drive Partition?

Computer hard drives (or hard disks) need to be partitioned before you can use them to store any data.

In fact, any type of storage device, USB drives (USB sticks), SD cards, external hard drives, whatever you can think of, need at least 1 partition before they can be used.

So although this guide is primarily going to focus on hard drives, it’s actually true for most storage devices.

What Are Hard Drive Partitions?

To help explain or to visualise what a partition is, let me ask you a question, “What have you got if you have a house without any walls”?

The answer is, of course, open space.

A house with no walls doesn’t exist.

And you can’t put, or store, anything inside it, because there is no inside.

The outside walls define the house. In effect they seperate, or partition, the outside from the inside.

An open field, green gras, a tree and blue sky.
Walls seperate the outside from the inside.

Hard Drive Partitions.

And it’s the same with a computer hard drive (disk).

The partition acts in much the same way as the walls of a house. The walls are the start and end of the building.

The hard drive partition defines the start and finish of the drive.

Hard drive with lid removed. A red circle defines the outer edge of the disk and a green circle defines the inner edge.
The partition is the space between the outer and inner limits of the disk.

Hard drives, USB drives, External hard drives, SD cards etc, are normally preformatted with 1 partition, so you don’t usually have to worry much about it. You can usually just plug it in and go.

The Hard Drive’s Partition Is A Container For Data.

The partition creates, or acts as, a container on the drive. Everything that is stored on the drive, is stored within the confines of the partition.

You can think of it as being like a super folder in Windows.

Hard drives (disks) are available in various capacities and from different manufacturers, by partitioning a drive, you’re defining the space on the disk that the computer can store it’s data.

Again, it’s similar to the walls of a house.

Multiple Partitions On A Hard Drive.

If we think of our fictional house, at the moment it only has 4 outer walls. That gives us just one very large inside space (or room).

But by adding partitioning walls, the inside space can be divided up into separate smaller spaces, or rooms.

These separate rooms can then become a bit more specialised, such as bedrooms, bathrooms, kitchen etc.

Hard drives can have multiple partitions.

They can be divided up into seperate storage areas.

Hard Drive with lid removed. Disk has concentric circles to represent different partitions.
What multiple partitons might look like on a hard drive.

Windows Disk Manager.

In fact, the hard drive on your computer will almost certainly have several partitions.

But you wouldn’t normally be able to see them.

If you open File Explorer, your most likely to see just one hard drive, the C: drive.

How To Use Windows File Explorer

C drive highlighted in File Explorer
There only seems to be one.

To view exactly how your hard drive has been partitioned, click the START button and then type

disk manager

And then press Enter on your keyboard.

Or click CREATE AND FORMAT HARD DISK PARTITIONS at the top of the menu.

Windows Start menu open. Disk Manager has been typed into search bo and "Create and format hard disk partitions" is highlighted on results list.
Opening Windows Disk Manager.

You should be able to see the various partitions on your drive.

You’ll probably have more than me, especially if you’re using a commercially built computer, such as a Dell, HP, Acer etc.

Callout indicates 3 partitons on a single drive.
You may have more pratitions than this.

Hidden Partitions On A Drive.

We’re back in our house again. Some houses have hidden rooms, secret rooms, that you normally can’t see or access.

The same is true for hard drives, they’ll often have hidden partitions that the operating system (Windows) can’t see or use.

Visible partitions appear in File Explorer as separate disks.

Windows treats each partition as if it were a different hard drive.

On my computer, the hard drive only has one visible partition, so it appears as a single disk.

C drive highlighted in File Explorer
Just the one for me. But you may well have more on your machine.

But we know from looking at Disk Management that the drive has got two hidden partitions.

Windows Disk Manager. Callout indicates 2 hidden partitions on one drive.
These two are hidden from the operating system.

If we create a second visible partition, then to Windows, it appears as if we have got two hard drives installed in the computer.

Whereas it’s only a single disk with two partitions.

Callout points to 2 visible partitions.
If you create 2 visible partitons in Disk Manager.
Callout indicates that there are now two drives in File Explorer.
In File Explorer, they’ll show as 2 drives.

Why Do We Have Hidden Partitions?

We have hidden partitions on our hard drives for exactly the same reasons we might have a hidden room in our house. To store stuff in that we don’t want other people to know about.

Often they’ll be created by your computer manufacturer to store the recovery data.

Back in the day, when you bought a new PC, it would come with several CDs/DVDs that you could use to do a factory reset on your machine. Nowadays all that data is stored on hidden partitions on your hard drive, which is only accessible through the computers recovery process.

Windows itself will also create at least a couple of hidden partitions.

On Your Home Computer

On your home computer, there are two main reasons for creating extra partitions on your hard drive.

The first reason is to install a second operating system.

You can have Windows 10 installed on one partition and perhaps Windows 7 on the other.
Or maybe you want to experiment with a Linux distro.

By dropping these operating systems on a separate partition, you don’t have to abandon Windows 10 completely, and you can save money by not buying a second hard drive.

The second reason is to store your data files (documents, pictures, music, videos etc).

By keeping them on a separate partition to the operating system (Windows), if you ever need to re-install, then your data can remain safe.

File Explorer open and 2 drives are shown.
You can store Windows on one partition and your data on the other.
Scroll to Top