Windows Server 2008 add Unallocated space to C drive

Updated on: July 11, 2019

This article introduces how to add Unallocated space to C drive in Windows Server 2008 R2. Add Unallocated space to system partition volume without losing data.

Can't add Unallocated space to C drive in Server 2008 DM

Microsoft improved the ability of native Disk Management (DM for short) by adding new Shrink and Extend Volume functions, so many server administrators try to repartition hard drive when system C drive runs out of space. In fact, Disk Management still cannot extend C drive by shrinking D or any other partitions. Because both functions have restrictions:

  • Shrink Volume can only make Unallocated space on the right after shrinking,
  • Extend Volume can only add Unallocated space to the left adjacent partition.

As you see in my server, the 20GB Unallocated space is made on the right of D after shrinking, it is nonadjacent to C: drive, therefore Disk Management cannot add Unallocated space to C drive. Drive E is on the right, so Extend Volume is grayed out, too.

Before adding Unallocated space to system partition C, you should move it from right of D drive to the left.

Server 2008 Disk Management cannot make or move Unallocated space to the left, so to accomplish these tasks, you need 3rd party partition tool.

Extend Volume disabled

Add Unallocated space to system partition with NIUBI

There is potential data loss risk when moving and adding Unallocated space, so remember to back up and run reliable partitioning software,

As the safest too, NIUBI Partition Editor provides 1 Second Rollback, Virtual Mode, Cancel-at-well technologies to ensure system and data intact. In addition, its advanced file-moving algorithm helps move partition 30% to 300% faster.

To move and add Unallocated space to C drive in Windows Server 2008 R2, you just need to drag and drop on the disk map of NIUBI. If you use any types of hardware RAID arrays, or VMware/Hyper-V virtual disk, there's no difference.

Download NIUBI Partition Editor, you'll see the main window with disk partition structure and other information, which is similar with Windows Disk Management. Available operations to selected disk or partition are listed on the left or by right clicking.

In Disk 0, there is 20GB Unallocated space which is shrunk from drive D.

NIUBI Partition Editor

Steps to add Unallocated space to system partition C in Windows Server 2008:

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.

Move Unallocated space

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 added into C: drive.

Move Unallocated space

Step 3: Click Apply on top left to execute. (Real disk partitions won't be changed until click Apply to confirm)

Add Unallocated space to C drive from other disk

In some servers, C drive is full but there is no or not enough unused space in other partitions on the same disk, some people are wondering if it is possible to shrink a volume in other disk to get Unallocated space, and then add into C drive. The answer is No, no software can add space from another separated disk. In this situation, you have two options.

If you use VMware or Hyper-V Guest server:

Increase virtual disk size, then Unallocated space will be shown as Unallocated space on the end of original disk. Follow the steps above to move and add Unallocated space to system C: drive.

If you use single physical disk or RAID array:

Copy original disk to a larger one, then Unallocated space will be also shows as Unallocated space on the end of disk. Follow the steps in the video to copy disk and add Unallocated space to C drive in Windows 2008 server:

Video guide

Besides shrinking, moving, extending and copying disk partitions, NIUBI Partition Editor helps do many other operations.

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