Merge Unallocated space in Windows Server 2008

by Jordan, Updated on: July 29, 2020

This article introduces how to combine Unallocated space in Windows Server 2008 R2, merge unallocated space to C drive (system partition) or to other volume.

As its name, Unallocated space is kind of disk space that is not allocated to any partition. Besides creating new volumes, Unallocated space can be added into an existing drive, then it will be converted to part of free space in this drive. In Windows Server 2008, you can get Unallocated space by deleting or shrinking a volume with its native Disk Management. Obviously, it is better to shrink partition than deleting. Although Disk Management can shrink partition to make Unallocated space without losing data (in most cases), it cannot merge Unallocated space to C drive or other partitions.

Can't merge Unallocated space to C drive with Server 2008 DM

When you shrinking partition with Disk Management, it only gives you an option to enter an amount of space, then Unallocated space is made on the right of this partition. It doesn't matter if you just want to create new volume with this space. But, it causes issue if you want to combine this Unallocated space to other partition, because Extend Volume function can only merge Unallocated space to the left contiguous partition.

Extend greyed

As you see in the screenshot, Extend Volume greyed out for both C: and E: drive after shrinking partition D. That means, Disk Management cannot merge Unallocated space to these partitions. Because, C: drive is nonadjacent and E: drive is on the right side.

If you don't want to use any third party software, the only way to extend C drive is by deleting D to get contiguous Unallocated space. To another data volume E, there's no way.

How to combine unallocated space to C drive with Server 2008 Disk Management:

  1. Press Windows and R together one the keyboard, input diskmgmt.msc and press Enter Disk Management.
  2. Right click D: and select Delete Volume, then the disk space will be converted to Unallocated.
  3. Right click C: drive and select Extend Volume.
  4. Unallocated space is selected by default, simply click Next till Finish.

Limitations to combine Unallocated space with Server 2008 DM

As I explained above, Disk Management can only merge Unallocated space to the left contiguous partition. Besides this shortage, there are 2 additional restrictions:

To merge Unallocated space in Windows Server 2008/2012/2016/2019, NIUBI Partition Editor is better choice.

How to merge Unallocated space with NIUBI Partition Editor

Download NIUBI Partition Editor and you'll see all disk partitions with structure and other information on the right. There is 20GB Unallocated space in Disk 0 that is shrunk from D: drive. Before adding Unallocated space to C drive, you should move it from right of D to the left.

NIUBI Partition Editor

Steps to merge Unallocated space to C: drive in Windows Server 2008 R2:

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

Move drive D

Then Unallocated space is moved to the left side.

Move partition d

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

Extend C drive

Then Unallocated space is combined into C: drive.

Drive D moved

Step 3: Click Apply on top left to execute.

If you want to merge Unallocated space to the right partition E, you can combine directly without moving E to the left. Right click E: and select "Resize/Move Volume", drag left border towards left in the pop-up window.

Extend E

Drive E extended

You can combine Unallocated space to either contiguous partition, no matter it is Primary or Logical, NTFS or FAT32.

Video guide to merge Unallocated space in Windows Server 2008 R2:

Video guide

When you moving Unallocated space with the contiguous partition, or merging Unallocated space to the right partition, all files in this partition should be moved to new locations. Therefore, it costs much time if there are large amount of files in this partition. Thanks to the advanced file-moving algorithm, NIUBI Partition Edition is much faster and saves much time. In addition, it has innovative 1 Second Rollback, Virtual Mode and Cancel-at-well technologies to protect system and data.

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