Windows Server 2012 Extend Volume greyed out

Updated on: June 5, 2019

This article explains why Extend Volume greyed out in Windows Server 2012 R2 Disk Management, and what to do when Extend Volume option is grayed out.

Why Extend Volume greyed out in Server 2012 DM

When system C: drive runs out of space, many people want to expand it with free space in other partitions. If it works, the low disk space issue can be fixed easily without wasting a long time to restore from backup or even starting from scratch.

Windows Server 2012 provides Extend Volume function in native Disk Management tool. It is able to extend both system partition and data volumes fast and without losing data. However, many people feedback that Extend Volume option is grayed out even after shrinking other partitions.

There are several reasons why Extend Volume greyed out in Server 2012 Disk Management. I'll explain one by one.

Reason 1: No adjacent Unallocated space

As we know, the size of a hard disk is fixed, a 500GB disk can't be decreased to 250GB or increased to 1TB. Before extending a partition, there must be Unallocated space. You can get this space by either deleting or shrinking other one. If there is no Unallocated space in the same disk, of course Extend Volume is grayed out for all partitions.

Many server administrators know about this, so they shrunk other allocated partition such as D, but Extend Volume is still disabled for C: drive.

Extend volume disabled

As you see in my server:

There is 18.96GB Unallocated space that is shrunk from drive D. Extend Volume greyed out for both C: and E: drive.

This is because:

C: drive is nonadjacent and E: is on the right of the Unallocated space, so Extend Volume doesn't work for them.

The same reason, Extend Volume is greyed out for drive D: after shrinking C: and E: in Disk Management.


If Disk Management can make Unallocated space on the left or move partition D to the other side, there is no such issue. This is the most common reason why cannot extend volume by shrinking other one in Server 2012 Disk Management.

Extend Volume disabled

Reason 2: Limitation of MBR disk

After deleting the right adjacent partition, you'll get the required Unallocated space, then Extend Volume will be enabled. In most of servers, programs or some Windows services are running from drive D, so you can't delete it to expand C. But if you want to extend D: drive, you can achieve by deleting other data volume E (if there is).

However, if the partition type of D and E are different, Disk Management bring you into trouble again.

Extend is grayed

As you see in the screenshot, Extend Volume still greyed out for D: drive after deleting E.

After deleting a Primary partition, the disk space will be converted to Unallocated, but the disk space will be shown as Free after deleting a Logical partition.

In MBR disk, Unallocated space deleted from a Primary partition cannot be extended to any Logical partition, Free space deleted from a Logical cannot be extended to any Primary partition. This is another serious restriction of Disk Management.

If you use GPT disk, there is no such issue.

To convert the 70GB Free space to Unallocated, right click the Free space select "Delete Partition". If there is another Logical partition behind E, you need to delete it and then delete the entire Extended partition.

Reason 3: Partition is not supported

Both Shrink and Extend Volume functions only support the partitions that are formatted as NTFS or without file system (RAW).

To show you this restriction, I converted drive D to FAT32. As you see, Extend Volume is grayed out, although there is 20GB Unallocated space next to it.

Extend Volume disabled

What to do when Extend Volume option is grayed out

It seems difficult, but it is easy to solve this problem. Firstly, let's see what to do if you have shrunk drive D: in Disk Management.

Download NIUBI Partition Editor and you'll see the main window with disk partition structure and other information. There is 20GB Unallocated space that is shrunk from D drive via Disk Management.

NIUBI Partition Editor

Steps to fix Windows Server 2012 Extend Volume greyed out issue:

Step 1: Right click drive D: and select "Resize/Move Volume", drag middle position towards right in the pop-up window:

Move rightwards

Then Unallocated space is moved to the left side.

Move Unallocated space

Step 2: Right click drive C: and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.

Expand C drive

Then Unallocated space is added into C: drive.

Unallocated add to C

Step 3: Click Apply on top left to take effect. (The operations before clicking Apply just work in virtual mode and are listed as pending.)

If Extend Volume greyed out issue is caused by not supported FAT32 partition, or the restriction between Primary and Logical partition. Follow the steps in the video:

Video guide

Remember the rule, right click a partition and select "Resize/Move Volume" feature, in the pop-up window:

Take care of data while shrinking and extending partition

There is potential system damage and data loss risk while resizing disk partition, so remember to back up first and use reliable partitioning software.

Better than other tools, NIUBI Partition Editor has innovative 1 Second Rollback technology. It is able to automatically reverts server to original status in a flash if encounter any error. If it happens, server could back online rapidly without modification. Other advantages include:

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