Enable Extend Volume option in Disk Management

By Andy, Updated on: December 26, 2019

This article introduces how to enable Extend Volume option in Windows 10/8/7 and Windows Server 2019/2016/2012/2011/2008 R2. 1 step to enable extend volume for system C drive in Disk Management.

In Windows XP and Server 2003, when system C drive is running out of space, if you don't want to use 3rd-party software, you have to back up, recreate partitions and restore everything. From Windows 7 and Server 2008, Microsoft added new Shrink Volume and Extend Volume functions to help change partition size without losing data. However many computer users feedback that Extend Volume greyed out after shrinking volume D, so they cannot extend C drive. This article introduces why Extend Volume is disabled and how to enable Extend Volume option in Disk Management.

Why Extend Volume is disabled in Disk Management?

There are many reasons why Extend Volume doesn't work, open your Disk Management and find out your disk partition details, then you'll know the corresponding reason in your computer.

  1. No contiguous Unallocated space on the right
    Extend Volume can only merge Unallocated space to the left contiguous partition. This is the reason why Disk Management cannot extend C drive and E after shrinking D.
  2. Only NTFS is supported
    Extend Volume can only extend partition formatted with NTFS file system, FAT32 and other types of partitions can't be extended even if there's right contiguous Unallocated space.
  3. Restriction between Primary and Logical partitions
    Unlike Primary partition, the disk space of Logical drive will be changed to Free after deleting, this Free space can't be extended to any Primary partition. Likewise, Unallocated space can't be extended to any Logical drives. This is the reason why Extend Volume still greyed out after deleting the right contiguous partition.
  4. Limitation of MBR disk
    The maximum size of a partition in MBR disk is 2TB, therefore, if C drive or other partition is 2TB, Disk Management cannot extend it even if there's right contiguous Unallocated space.

How to enable Extend Volume for system C drive

In most of personal computers and Windows servers, system C drive is formatted with NTFS by default. Therefore, if your system disk is GPT, reasons 1 is the most possible why Extend Volume greyed out for C drive. If you use MBR disk, check if the right contiguous partition (D) is a Logical drive.

If you shrunk drive D but extend C drive greyed out in Disk Management, there are 2 solutions with and without third party software.

Solution 1: delete the right contiguous partition

Note: the right contiguous partition D must be Primary, do NOT delete D if you installed programs or Windows services into it.

If you can delete the adjacent partition D, its disk space will be converted to Unallocated and behind C drive. Follow the steps to enable Extend Volume for system C drive:

  1. Back up or transfer all files in drive D to other place.
  2. Open Disk Management, right click D: and select Delete Volume.
  3. Right click C: drive and select Extend Volume.
  4. In the pop-up Extend Volume Wizard window, simply click Next till Finish.

Solution 2: move partition D and Unallocated space

If you cannot delete drive D or it is a Logical partition, Disk Management is useless, instead, you need to run third party software to move Unallocated space from right of D to the left.

How to enable Extend Volume option by moving Unallocated space:

  1. Download and run NIUBI Partition Editor, right click drive D and select "Resize/Move Volume", drag the middle towards right in the pop-up window. Then Unallocated space will be moved to the left side, Extend Volume will be enabled for C drive in Disk Management.
  2. Right click C: drive and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.
  3. Click Apply on top left to execute, then Unallocated space will be merged into C drive.

There is free edition for Windows 10/8/7/Vista/XP home computer users.

Video guide

How to enable Extend Volume option for D and other volume

To data volume, if it is a FAT32 partition, you may convert it to NTFS. You can also convert partition between Primary and Logical to enable Extend Volume. But with NIUBI Partition Editor you can shrink and extend these partitions directly. If Extend Volume greyed out because your MBR disk is 2TB+, convert it to GPT with NIUBI, follow the steps in the video:

How to shrink and extend partition:

Video guide

How to convert MBR disk to GPT:

Video guide

Besides shrinking, moving and extending partitions, NIUBI Partition Editor helps do many other disk and partition operations. Better than other tools, it has innovative 1-Second Rollback, Virtual Mode, Cancel-at-well technologies to protect system and data. In addition, it is 30% to 300% faster because of the advanced file-moving algorithm.