Cannot extend volume

Fix Extend Volume greyed out in Windows 10

From Windows Vista, Microsoft added advanced Shrink Volume and Extend Volume functionalities in Disk Management snap-in, with which you can decrease and increase the size of partitioned volume without reinstalling Operating System. Windows 10 inherited these functions, so you can resize volume in some part. However, many people feedback Extend Volume is grayed out in Windows 10 Disk Management when expanding a volume.

After decrease drive D with Shrink Volume, Extend Volume is disabled for C drive. So in this article I’ll introduce how to fix Extend Volume greyed out in Windows 10.

Extend volume grayed out

Why Extend Volume greyed out in Windows 10

Extend Volume grayed out could be seen in several situations. To better explain, I’ll explain one by one.

1. Extend volume directly

To expand a drive with Extend Volume, there must be adjacent Unallocated space, but some people don’t know about this, so they try to extend volume directly, of course it is impossible.

Extend volume grayed

2. Unallocated space is not adjacent

This is the most common scenario in Windows 10. Some people decrease drive D with Shrink Volume:

Shrink D

10GB Free space is generated behind volume D, as you see, Extend Volume is still greyed out when right click C drive.

Extend C grayed

3. Logical partition is special

If Shrink Volume does’t work, what about deleting the adjacent volume D to get Unallocated space? If you want to do this, 2 points you should know:

  1. All Windows services and programs in D stop working after deleting this volume. In addition, you’ll lose data if you forget to back up or transfer before deleting.
  2. If volume D is Logical, you cannot solve this problem by simply deleting it.

Right click D and select Delete Volume:

Delete D

As you see, Extend Volume is disabled for C drive, too.

Extend C greyed

4. Delete Extended partition

If volume D is a Primary partition, the disk space will be converted to Unallocated after deleting. If it is a Logical partition, the space shows as Free instead.

Tips: in a MBR style hard disk you can create 4 Primary partitions at most, or 3 Primary partition plus an Extended Partition. In the Extended Partition, there could be many Logical Partitions.

In this situation, to convert the Free space to Unallocated, you have to delete the entire Extended partition, but first, you need to delete all other Logical partitions one by one.

Delete E

Delete the Extended partition:

Delete extended partition

As you see, Extend Volume becomes available when right clicking C drive.

Extend volume available

Reasons why Extend Volume grayed out in Windows 10

  1. From Microsoft explanation, only NTFS and RAW format partition can be extended, FAT32 and other types of partitions are not supported.
  2. There is no adjacent Unallocated space. Only when the Unallocated space is adjacent and on the right side of C drive, you can expand C drive with Extend Volume.
  3. If the adjacent drive D is Logical Partition, you cannot extend C drive by simply deleting D. You should delete all Logical partitions in the Extended Partition and then delete the entire Extended Partition.

Fix Extend Volume grayed out with partition software

It seems complicated, but you can solve this problem easily. Download NIUBI Partition Editor, right click drive D and select “Resize/Move Volume“.

Resize/Move Volume

In the pop-up window, drag the middle position rightwards to move it.

Move volume

After that, the Unallocated space will be moved to behind C drive.

Unallocated moved behind C

You may either expand C drive under Windows 10 Disk Management or continue with this partition software.

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

Extend C drive

Tips: If there is adjacent free space, but Windows 10 Extend Volume greyed out because of nonsupport FAT32 or Logical partition, simply right click C drive to merge the free space without moving any partition.


Windows 10 Disk Management has the ability to shrink and extend partitioned drives, but it cannot help you extend a drive by shrinking other drive. In most conditions, you still need third party partition software.

When Extend Volume greyed out in Windows 10 Disk Management, you just need to move the Unallocated space to behind C drive, and then this problem will be solved. Beside resizing and moving partitions, NIUBI Partition Editor Professional help you create, delete, format partition, change drive letter, copy, hide, set active, convert, defrag, check partition and much more.

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Fix Extend Volume grayed out on Windows 10 with ease
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