How to Partition a Hard Drive in Windows 10

To partition a hard drive in Windows 10, right-click Start and select Disk Management. Right-click the drive you want to split, select Shrink Volume, and enter how much space to free up. Then right-click the new Unallocated space, select New Simple Volume, and follow the wizard to create and format the partition.

The same steps work for internal hard drives, SSDs, laptop drives, external drives, and USB flash drives.

Applies to: Windows 10. You need an administrator account. Checked against Microsoft Support on September 25, 2026.

Why partition a drive?

• Keep files separate from Windows. If you ever reset or reinstall Windows, files on a separate data partition are easier to keep safe.
• Stay organized. A separate drive letter for photos, projects, or games makes them easy to find and back up.
• Run two operating systems. Dual-booting Linux or another copy of Windows needs its own partition.

A partition is not a backup. If the physical drive fails, every partition on it is lost, so keep copies of important files on another drive or in the cloud.

Before you start

• Back up your files. Shrinking is usually safe, but a power cut or disk error could cause data loss.
• Check free space. You can only shrink a drive by the amount of free space it has, and sometimes less.
• Leave system partitions alone. Don’t change partitions labeled EFI System Partition, Recovery, or anything without a drive letter that you don’t recognize.

Step 1: Open Disk Management

Right-click Start and select Disk Management. You can also press Windows + R, type diskmgmt.msc, and press Enter.

Step 2: Make space by shrinking a volume

1. Right-click the partition you want to split, such as (C:), and select Shrink Volume.

2. In Enter the amount of space to shrink in MB, type the size of the new partition. For example, 102400 MB is 100 GB.
3. Select Shrink. A black bar labeled Unallocated appears.

A new or empty drive may already show Unallocated space. If so, skip to step 3.

Step 3: Create the new partition

1. Right-click the Unallocated space and select New Simple Volume.

2. Select Next, keep the size or enter a smaller one, and select Next.
3. Choose a drive letter and select Next.
4. Choose NTFS as the file system, type a Volume label such as Data, and keep Perform a quick format checked.
5. Select Next > Finish. The new drive appears in File Explorer.

Partition from the command line with DiskPart

DiskPart does the same job as Disk Management. It’s useful if Disk Management won’t open or you’re working from a recovery command prompt. Typing the wrong number can erase the wrong drive, so check each step.

1. Open Command Prompt as an administrator, type diskpart, and press Enter.
2. Type list volume and note the number of the volume to shrink, such as C.
3. Type select volume 2, using your volume’s number.
4. Type shrink desired=102400 to free 100 GB. Change the number in MB as needed.
5. Type create partition primary.
6. Type format fs=ntfs quick label=Data.
7. Type assign letter=E, choosing any free letter, then exit.

The new drive appears in File Explorer straight away.

Partition an external drive or USB flash drive

Connect the drive, open Disk Management, and find it by its size. It’s usually Disk 1 or higher. Then follow steps 2 and 3.

• Use exFAT instead of NTFS if you’ll also use the drive on a Mac.
• A new drive may ask to initialize. Choose GPT for drives over 2 TB or on newer PCs, and MBR for older ones.
• Repartitioning a drive erases it if you delete its existing partitions. Copy your files off first.

If Shrink Volume won’t give you enough space

Windows can’t move some system files, so it may offer less than your free space. Try these:

• Run Disk Cleanup and empty the Recycle Bin.
• Turn off hibernation temporarily with powercfg /h off in an admin Command Prompt, then turn it back on with powercfg /h on afterward.
• Restart and try again.

When you need more than Disk Management

Disk Management can only extend a partition into empty space directly to its right, and it can’t move partitions. If you need to resize a partition that isn’t next to the free space, merge partitions without deleting one, or move a recovery partition out of the way, a third-party partition manager can do it. Many have free versions. Back up the drive first, since moving partitions carries more risk than shrinking one.

Frequently asked questions

Will partitioning delete my files?

Shrinking a volume and creating a new partition doesn’t delete files. Deleting or formatting a partition does.

How many partitions can I make?

On a GPT disk, up to 128. On an MBR disk, up to four primary partitions, or three plus an extended partition.

Should I partition an SSD?

You can, but it doesn’t make an SSD faster. Partition it only if you want to keep files organized separately.

Can I undo a partition?

Yes. Right-click the new partition in Disk Management and select Delete Volume, which erases anything on it. Then right-click the original partition, such as C:, and select Extend Volume to take the space back. Extend only works when the free space sits directly to the right of that partition.

To erase and set up a whole drive, see how to format a drive in Windows 10.

To add unallocated space back to a drive, see how to extend the C drive in Windows 10.

To combine two partitions into one, see how to merge partitions in Windows 10.

For all the ways to open Disk Management, see how to open Disk Management in Windows 10.

To change the letter of a drive after you make it, see how to change a drive letter in Windows 10.

To see the partitions you already have, see how to view partitions in Windows 10.

To find your new drive later, see how to access the C drive in Windows 10. Microsoft’s guide is Disk Management in Windows. More help is on our Windows Help & Guides page.

Related: how to delete a recovery partition in Windows 11.