By Emily / Last Updated April 21, 2022

Windows "Extend Volume" greyed out in Disk Management

In order to meet the need of users, Microsoft released a built-in tool called Disk Management which can help users to delete/format/create partitions. It has added two features - shrink volume and extend volume to Disk Management in Windows 11, 10, 8, 7, XP, and Vista. The improvements make the resizing partition become realizable in theory. Gradually, this tool is widely used to manage disk partitions. However, sometimes we may find the option "Extend Volume" greyed out. Why cannot we use the feature to extend volume in Windows?

Cannot Extend

Why "Extend Volume" grayed out and how to fix it?

In fact, "Extend Volume" option under Disk Management tool is only available when there is contiguous unallocated space behind the volume you want to extend. As there is no unallocated space after the C partition drive, so "Extend Volume" option is not available. So, we need an unallocated place behind the goal partition (drive: C). Theoretically, we can shrink volume D for unallocated space, but you will find the unallocated space locates behind drive: D, not drive: C. And you cannot move that unallocated space.

As the only workaround to fix it, you have to make the drive: D an unallocated place by deleting it, but you will lose all data on that partition. To avoid that, you can back up the D partition beforehand. but this will cost you too much time. Therefore,  many users are looking for another shortcut to get around "extend volume greyed out" without data loss and costing lots of time.

Evade  "Extend Volume" greyed out issue easily

Here AOMEI Partition Assistant Professional is highly recommended. It includes powerful functions such as resize/move partition, split partition, merge partitions, allocate free space, dynamic disk management, create partition, wipe hard drive and partition, and so on. In addition, it allows you to create bootable USB drive in case that you need to manage the disk partition without loading Windows, such as formatting system drive.

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When the "extend volume" is not available, you can try the "Merge Partitions" feature of AOMEI Partition Assistant Professional.

Before you do:
If the partition has running applications, AOMEI Partition Assistant will suggest you close them or perform the operation under PreOS Mode.
You can merge data partition into system boot drive, however, you cannot merge system boot drive into data partition; "System Reserved" partition could not be merged.
You can only merge 2 adjacent partitions every time. On the contrary, you can merge any unallocated space into a partition.

Step 1. Install and launch the software. You can see there is unallocated space next to the D drive on the main interface. (If there is no unallocated space, you can use resize the partition to get unallocated free)

PA Professional

Step 2. Right-click C drive and select Merge Partitions.

Merge Partitions

Step 3. Choose unallocated space, and then click OK.

Add Unallocated Space to C Drive

Step 4. Click Apply, you will see the C drive has been extended.

Apply Merge Partitions


From the steps mentioned above, you can see clearly that the unallocated space is adjacent to D drive, however, with the feature of Merge Partitions, you do not have to worry the function will be grayed out; you can extend C drive freely. Furthermore, the easy-to-use interface makes you finish the task in seconds.

If there is no unallocated space on the hard disk, you can switch to the "Allocate Free Space" feature, which allows you to assign some free space from one partition to another.

Allocate From D To C


The software solves the "Extend Volume" greyed out issue in Disk Management. You can use it to extend any drive even though there is no unallocated spade next to the to-be-extended drive. So it is a good partition manager for you. Besides, when you find the Convert to MBR Disk or Convert to GPT Disk option greyed out in Disk Management because there are partitions, the AOMEI Partition Assistant can also help avoid such issues easily without deleting any partitions.

In order to meet the needs of various users, there are different versions for different people. For instance, for home users, Partition Assistant Professional is your good choice. For enterprise users, Partition Assistant Unlimited Edition is a better choice to support unlimited usage within one company. Also, you can use Partition Assistant Technician Edition to provide charged technical services to your clients. Please choose a proper edition based on your needs.