How to Shrink a Partition in Windows 10

Today, we will see how to shrink a partition or disk on your drive in Windows 10. This can be useful if you have extra space on your drive which you would like to use for installing another OS in a dual boot configuration. Or if you have a new computer with only one big partition created by the vendor, you might want to split it into two or more partitions to separate your personal data from the system drive.

In older Windows releases, shrinking the volume required a third-party tool. Modern Windows versions like Windows Vista, Windows 7, Windows 8.1 and Windows 10 allow shrinking partitions with free space in order to reduce their size and use that free space for creating another partition or installing a different operating system.

Many users prefer to create multiple partitions on their drive to avoid storing all data on the system partition which has Windows installed. Traditionally, the system drive is your C: drive. If it is large enough, you can shrink it and have partitions D:, E: and so on.

Windows 10 offers a number of methods that you can use to shrink your partitions. These include Disk Management, the console tool "DiskPart", and PowerShell.

To shrink a partition in Windows 10, do the following.

1. Press the Win + X keys together.
2. In the menu, select Disk Management.
3. In Disk Management, right-click on the partition you would like to shrink.
4. Select Shrink volume in the context menu.
5. Type by how many MBs you want to shrink the partition, and click on Shrink.

You are done.

The process takes a few seconds but Disk Management shows no progress bar. Once the process is done, it will show you Unallocated space on the drive.

You can create a new partition with the Unallocated space if you need. Alternatively, you can reboot and install another operating system for a dual boot configuration.

Note: If for some reason, you are unable to Shrink your partition or if Disk Management gives you an error, you can try the following. Open System Protection and disable it temporarily for the partition which you wish to shrink.

Shadow copies, Restore Points and such system data sometimes prevent Windows from the shrinking the partition and restrict the quantity by which it can be shrunk. The maximum number of reclaimable bytes might be higher once system protection is disabled for the partition. You can re-enable System Protection once you have shrunk the partition.

Shrink a partition using DiskPart

DiskPart is a text-mode command interpreter bundled with Windows 10. This tool enables you to manage objects (disks, partitions, or volumes) by using scripts or by direct input at the command prompt.

Tip: DiskPart can be used to wipe a disk or a partition securely.

To shrink a partition using DiskPart, do the following.

1. Open an elevated command prompt.
2. Type diskpart.
3. Type list volume to see all drives and their partitions.
4. Look at the ### column in the output. You need to use its value with the command select volume NUMBER. Substitute the NUMBER portion with the actual partition number you want to shrink.
5. Type shrink querymax to see the maximum number of reclaimable bytes that you can shrink the partition by.
6. To shrink by maximum size allowed, just type shrink and press the Enter key.
7. To shrink by the specified size, type the command shrink desired=size_in_MB. Substitute 'size_in_MB' with a value that is not greater than the maximum number of reclaimable bytes.

You should see the message DiskPart successfully shrunk the volume by: value here.

Finally, you can use PowerShell for doing the same operation.

Shrink a partition using PowerShell

1. Open an elevated PowerShell instance.
2. Type Get-Partition to see the list of your partitions.
3. Note the drive letter and type the next command:

   Get-PartitionSupportedSize -DriveLetter drive_letter

   Replace the "drive_letter" portion with the actual value to see the minimum and maximum size for this partition (SizeMin and SizeMax).

4. The next command will shrink your partitions:

   Resize-Partition -DriveLetter "drive_letter" -Size size_value

   Supply the correct drive letter and its new size in bytes. The value should be between SizeMin and SizeMax values you've got from the previous step. This way, you can shrink or expand the partition.

   

Tip: The -Size argument accepts size modifiers like:

-Size 1KB - for one kilobyte.
-Size 1MB - for one megabyte.
-Size 1GB - for one gigabyte.

That's it!