How to Extend a Volume in Windows PC

Sometimes, users run short of storage space on a particular drive and want to increase it. Windows offers built-in tools that help you extend volume on Windows on any of your partitions with some restrictions. In this post, we explore and learn how to use those tools to increase storage space.

What You Should Know Before Extending a Volume in Windows

Disk volumes are logical divisions of a physical storage device for storing and accessing data. The process of storing and accessing the data is defined by the File System used to format the drive. Unlike partitions, a volume can be assigned names and span multiple physical storage devices or partitions.

Extending a volume can increase the storage capacity of the particular volume by roping in the empty spaces of the storage drive.

However, to add space to an existing volume:

  • It should be unallocated, i.e., not an existing partition.
  • If you have an unused partition next to the partition you want to extend, you can delete the former, create unallocated space, and add it.
  • It should not be a part of any other existing volume, i.e., if there is free space in the partition, it cannot be moved to the one you want to extend.
  • It should be available next to the partition volume you need to extend. If the unallocated space is available between two volumes, it cannot be added.

Note:  Volumes that are formatted with NTFS and/or ReFS File Systems can only be extended. Drives with other file systems must be formatted to NTFS and/or ReFS before extending the volume.

How to Extend Volume on Windows

How to Extend a Volume in Windows PC

Broadly, there can be two different approaches for extending a Disk Volume in Windows:

  1. Using Disk Management option.
  2. Using PowerShell.

You will need an administrator account to execute these methods. Make sure you have a backup of all the files, preferably an image of the current system, in case you need to restore.

1] Extend Disk Volume using the Disk Management option

  • Search for Computer Management by typing the same in the Search Box on the Windows Taskbar.Extending Disk Vol
  • Once the option comes up, click it to open the Computer Management window. If the user is not logged in as an Administrator, right-clicking on the Computer Management option and selecting the Run as Administrator option followed by entering the Admin login credentials after clicking Yes will open it in the desired mode.
  • Click on Storage > Disk Management to open the Disk Management options in the Disk Management tool.Compuiter Management Disk Management
  • Right-click on the Disk Volume that needs to be extended and Click on Extend Volume.Extend Volume Disk Management
  • Click on Next to open the following window for Select Disk.
  • Enter the required space to be extended in the Select the Amount of Space in MB.
  • Click on Next > Finish to complete the process.

2] Extend Disk Volume using PowerShell script

Right Click on the Start (Windows) button and select Windows PowerShell. Enter the below-mentioned command to specify the volume name to be extended, followed by the script for partition size and volume resize.

PowerShell Disk Management Command

The above image shows the standard command that one can use. The explanation is below, followed by the stepwise command that anyone can use.

  • Specify the Volume Name:
 $drive_letter = "C"
  • To get the partition sizes and then volume resize:
$size = (Get-PartitionSupportedSize -DriveLetter $drive_letter)
Resize-Partition -DriveLetter $drive_letter -Size $size.SizeMax

Now that you know the command, let’s use an example for better clarity. 

For example, to create a 600 GB by extending the volume from 500 GB for the 3rd partition of Disk 2. Follow the steps as suggested:

  • Check the size of the partition, disk number, and drive letter using the Get-Partition command:
Get-Partition -DiskNumber 2 -PartitionNumber 3 Disk Number: 2

Checking the size of the partition using Get Partition Command

  • Resize the Partition using the Resize-Partition command:
Resize-Partition -DiskNumber 2 -PartitionNumber 3 -Size (600GB)

The partition is now 600GB.

Additionally, to resize using the maximum space available, considering the available space left is 800 GB:

Resize-Partition -DiskNumber 2 -PartitionNumber 3 -Size (800GB)

The above message will be displayed when the resizing is successful.

  • Use the following command to check the partition once again to confirm the Extension of the Volume:
Get-Partition -DiskNumber 2 -PartitionNumber 3 Disk Number: 2

check partiton size using Get-Partition Command


Extending a volume is an easy process. However, it becomes complicated when you don’t have enough unallocated space or do not know how to reuse it by deleting an unused partition. On top of that, if you need to create unallocated space from an existing partition, it is not possible.

This post has shared the steps you can use to Extend Volume on Windows PC and the pre-conditions one needs to meet. Let us know if you get stuck somewhere.

Sandip Basu
Sandip has worked as an IT solutions consultant for the last 15 years and specializes in troubleshooting software and hardware.


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