Move/Merge unallocated space in Windows Server 2022/2025

by John, Updated on: May 29, 2026

Unallocated space does not belong to any partition. In addition to creating a new volume, it can also be merged into another partition on the same disk. To merge unallocated space in Windows Server 2022/2025, the built-in Disk Management tool can only help under certain conditions. For example, it cannot merge unallocated space into the adjacent partition on the right. In addition, it cannot move unallocated space or merge it into a non-adjacent partition on the disk. This article explains how to move and merge unallocated space in Windows Server 2022/2025 using Disk Management and safe partitioning software.

Merge unallocated space

How to merge unallocated space in Server 2022/2025

As mentioned above, Disk Management can help merge unallocated space, but it only works under restricted condition. Limitations to merge unallocated space with Disk Management:

  1. It can only merge unallocated space into NTFS or ReFS partitions; FAT32 and any other file systems are not supported.
  2. It can only merge unallocated space into the adjacent partition on the left.
  3. It cannot move unallocated space on a disk.

If your disk partition configuration meets these requirements, you can complete the operation using Disk Management. Otherwise, third-party software is required.

How to merge unallocated space in Windows Server 2022/2025 via Disk Management:

  1. Right-click the partition on the left and select "Extend Volume".
  2. Simply click Next until Finish in the pop-up window.

If you want to add unallocated space to the partition on the right, Disk Management cannot help you. For example, if you have shrunk the D: drive and created unallocated space, follow the steps below to merge it into the E: drive:

  1. Download NIUBI Partition Editor, right-click the E: drive and select "Resize/Move Volume". Drag the left border to the left to merge the unallocated space.
  2. Click Apply in the top-left corner to execute the operation.

How to move unallocated space in Server 2022/2025

First of all, you should know that unallocated space can only be moved within the same disk. No software can move unallocated space to another disk, because the size of a physical disk is fixed. A 500 GB disk cannot be reduced to 400 GB or increased to 600 GB.

For example, if you have shrunk the D: drive using Disk Management, the unallocated space will be on the right side of D: instead of C:. Before extending the C: drive, you need to move the unallocated space from the right side of D: to the left. Once the unallocated space becomes adjacent, you can extend the C: drive easily in seconds.

How to move unallocated space in Windows Server 2022/2025 to the left:

  1. Right-click the D: drive in NIUBI Partition Editor and select "Resize/Move Volume".
  2. Drag the middle of the partition to the right in the pop-up window; then the unallocated space will be moved to the left.
  3. Click Apply in the top-left corner to execute the operation.

Watch the video to learn how to operate:

Move unallocated space

Besides moving/merging unallocated space in Windows Server 2022/2025 and earlier versions, NIUBI Partition Editor helps you perform many other disk partition management operations, such as shrinking, extending, merging, converting, defragmenting, cloning, hiding, wiping partitions, and scanning for bad sectors.

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