From Windows 7, Microsoft enhanced the ability of native Disk Management tool by adding new Shrink Volume and Extend Volume functions, with which you can resize partition without losing data (in most cases). However, both functions only work under specific conditions. Windows 8/10 inherited the same functions without any improvement, so many people feedback that Extend Volume is grayed out and they cannot extend partition. In this article I'll introduce all probable reasons why Extend Volume greyed out in Windows 10/8/7 Disk Management and how to solve this problem easily.
Why Extend Volume greyed out in Windows 10 Disk Management:
Reason 1: No adjacent Unallocated space on the right
As the name, Unallocated is kind of a space that is not allocated to any partition. In Windows XP Disk Management, Unallocated space can only be used to create new partition, but in Windows 10/8/7, it can be used to expand other drive.
Note: the size of a physical hard disk is fixed, a 256GB disk cannot be decreased to 128GB or increased to 512GB, so before extending a partition, there must be Unallocated space on the same disk. You can get Unallocated space by deleting or shrinking other volume. It is better to shrink partition, because you won't lose data in it.
Then why extend C: drive greyed out in Windows 10 Disk Management after shrinking D? From Microsoft explanation, Extend Volume function only works when there is adjacent Unallocated space on the right side. When you shrink a partition with Disk Management, Unallocated space can only be made on the left. Therefore, Unallocated space that shrunk from D is non-adjacent to C: drive. This is the reason why Extend Volume is disabled for C drive in Windows 10/8/7 Disk Management.
To show you the truth, I shrunk D: drive with Disk Management in my Windows 10 laptop.
As you see in the screenshot:
- Extend Volume greyed out for C drive, because the Unallocated space is nonadjacent to it.
- Extend Volume is also disabled for E drive, because Unallocated space is on its left side.
- Only drive D meets the requirement, so Extend Volume is activated.
Reason 2: File System is not supported
Another common reason why Extend Volume greyed out in Windows 10/8/7 Disk Management is related to file system.
Both Shrink and Extend Volume functions only support NTFS file system, FAT32 and any other types of partitions cannot be resized via Disk Management. To show you the truth, I formatted drive D from NTFS to FAT32. As you see, Extend Volume is grayed out for D drive.
In general, the system partition is formatted with NTFS by default when installing Windows, so this issue is just common for data partition.
If you initialized your hard disk as MBR, there could be 2 additional reasons why Extend Volume is grayed out in Windows 10/8/7 Disk Management.
Reason 3: Different partition type
As I show you above, Disk Management tool cannot extend a volume by shrinking another one, so some people are wondering if it's possible to delete the adjacent D: drive, then its disk space will be converted to Unallocated, therefore Extend Volume is enabled for C: drive. It works indeed on GPT disk, but on MBR disk, it depends.
Don't delete D to expand C drive if you installed programs or any Windows service into it.
As you see in my computer, Extend Volume is still disabled for C drive after deleting D.
Then why Extend Volume greyed out in Windows 10/8/7 even if I deleting the contiguous partition on the right?
On GPT disk, you can create many partitions and all are Primary, but on MBR disk, you can only create 4 partitions if they are all Primary. Because there are only 4 entries in Master Boot Record, from which Operating System can locate the position of each partition.
To create more than 4 partitions, 1 of the entry must be assigned to the Extended partition. Extended partition works like a container and all Logical drives must be created inside of it.
Unlike Primary partition whose disk space will be converted to Unallocated after deleting, disk space of a Logical partition will be converted to Free after deleting. Free space is still a part in the container (Extended Partition), so it cannot be combined to any Primary partitions.
Likewise, Unallocated space deleted from a Primary partition cannot be extended to any Logical drive via Windows Disk Management.
Reason 4: 2TB restriction on MBR disk
Another major limitation of MBR style disk is that you can only create maximum 2TB partition on it. If you initialize a 4TB hard disk as MBR, you can only use 2TB space, the remaining space will be shown as Unallocated. When you right click this Unallocated space in Disk Management, all options are grayed out.
As you see in the screenshot, F: drive is NTFS and there's contiguous Unallocated space on the right, but Extend Volume is still grayed out in Windows 10 Disk Management. Before extending F drive past 2TB, you must convert this MBR disk to GPT.
What to do when Extend Volume is disabled in Windows 10/8/7
Solution 1: Move Unallocated space
When Extend Volume greyed out for C drive after shrinking D or other volume, you must move Unallocated space next to C drive and then combine it with NIUBI Partition Editor.
How to fix Windows 10 Extend Volume greyed out for system C drive:
- Download NIUBI Partition Editor, right click D: drive and select "Resize/Move Volume", drag the middle towards right in the pop-up window, then Unallocated space is moved to the left side.
- Right click C: drive and select "Resize/Move Volume" again, drag right border towards right in the pop-up window, then Unallocated space is combined to C: drive.
- Click Apply on top left to confirm and execute.
Follow the steps in the video:
To another contiguous data volume E, you can merge Unallocated space to it directly without moving. To do this, right click E and select "Resize/Move Volume", drag left border towards left in the pop-up window.
Solution 2: Resize volume with partition editor
If Extend Volume greyed out because you try to extend a FAT32 partition or the type of partitions that you want to shrink and extend are different, resize with NIUBI Partition Editor. There's no difference while resizing NTFS or FAT32 partition, Primary or Logical partition. Follow the steps in the video:
Solution 3: Convert mbr disk to gpt before expanding
If you want to extend a partition past 2TB, follow the steps in the video to convert MBR disk to GPT and then you can extend partition with Unallocated space.
Because Windows 10/8/7 Disk Management has many restrictions, you may encounter many problem while shrinking and extending partition. This article introduces the common reasons why Extend Volume greyed out in Windows 10/8/7 Disk Management and how to solve this problem with ease. Follow the corresponding solution according to your own disk partition configuration.
Besides shrinking, extending and moving partitions, NIUBI Partition Editor helps do many other operations such as merge, convert, defrag, hide, wipe partition and scan bad sectors. Better than other tools, it has unique 1-Second Rollback, Virtual Mode and Cancel-at-well technologies to protect your system and data.