How to extend volume of C drive or data partitions?

When a partition especially the system C: drive running out of free space, you can expand it with Unallocated space or the unused space in other drives. Nowadays, nobody would like to back up and start from scratch. There are several ways to extend volume of C drive or data partitions, such as Windows built-in Diskpart command and Disk Management, as well as 3rd party software. In this article, I’ll give detailed steps of how to extend disk partitions.

  1. Extend volume with Diskpart command
  2. Extend volume under Disk Management
  3. Extend volume with Partition Magic Server

Extend volume with Diskpart command

DiskPart is a text-mode command line tool interpreter which enables storage objects such as disks, partitions or volumes configuration and management from a script, remote session, or direct input from a command prompt.

For Windows Server 2003 and XP, There is no GUI function in Disk Management console, the only Windows built-in utility to extend volume is Diskpart command, steps:

Step1: Press ‘Windows‘ and ‘R‘ key on the keyboard, type ‘cmd‘ and click ‘OK‘ or press ‘Enter’.

MS-DOS command line window will be opened.

Step 2: In the command line window, type diskpart and press ‘Enter’.

Diskpart command

Step 3: Type “list volume” to display the existing volumes on the computer.

List volume

Step 4: Type “select volume X”, X is the number or drive letter of the partition that you want to extend.

Select volume

Step 5: Type extend [size=n] [disk=n] [noerr].

Diskpart error

As there is no Unallocated space behind partition E, you cannot extend this partition. To show the result, I delete Partition F and try Extending volume again.

Diskpart extended

Shortages of extending volume with diskpart

  1. The volume must be formatted with NTFS file system.
  2. For Basic volumes, Unallocated space for extension must be the next contiguous space on the same disk.
  3. The system C volume can only be extended by running Diskpart command via bootable CD.
  4. Only when you delete a data partition and get some Unallocated space, you can extend system C drive.
  5. It works by command line and hard to use for many users.
  6. Incorrect operations cannot be undone.

Extend volume under Disk Management

In Windows 10/8/7/Vista and Server 2016/2012/2008, you can extend C drive or data volume with GUI function under Disk Management snap-in. However, you can only extend the volume when there is adjacent Unallocated space behind. How to extend C drive:

Step 1: Right-click C drive or any other partition you want to extend and select “Extend Volume…”

 Extend volumeStep 2: In the pop-up window, select available disk and free space. You can modify the default amount if you do not want to use the entire Unallocated space to extend partition.

Add space

Step 3: Confirm the operation and click “Finish” to proceed.

Confirm extending

Partition extending operation complete in a short time.

Partition extended

Only when there is adjacent Unallocated space, you can extend a partition. From the screenshot below, “Extend Volume” is grayed out when you right click C drive. The 20GB Unallocated space can only be used to extend data drive E.

Extend unavailiable

There is no such limitations by using 3rd party software, you can extend any volume with the unused space in other drives of the same disk.

Extend volume with 3rd party software

Step 1: Download NIUBI Partition Editor, right click D: drive and select “Resize/Move Volume“.

Drag to resize

Step 2: In the pop-up window, drag the left border rightwards to generate free Unallocated space.

Shrink d drive

Drag to resize

Click OK and back to the main window, where 20GB Unallocated space created behind C: drive.

Unallocated space

Step 3: Right click C drive and select “Resize/Move Volume” again, in the pop-up window, drag the right border rightwards to hold the Unallocated space.

Extend C drive

Hold unallocated space

Click OK and back to the main window, where C drive extended to 60GB by holding the 20GB free space from D. Press Apply on top left to execute, done!

Partition resized

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