Extend C: drive partition on Windows Server 2012

Updated on: November 16, 2019

This article introduces how to extend C: drive on Windows Server 2012 (R2) without data loss. Shrink volume D: or E: to extend partition C, or enlarge C volume with other disk.

When system partition C runs out of space, nobody likes to start from scratch or restore from backup. Instead, you can enlarge C drive with other partition or disk in a short time. However, it is not an easy task for many server administrator. In this article, I'll show you 4 ways to extend partition C in Windows Server 2012 with detailed steps. Check your server disk partition configuration and select the corresponding method.

1. Extend C drive by deleting D

This method is used when you cannot install third party tool and no programs or services running from the adjacent partition D.

Windows Server 2012 native Disk Management tool has Shrink Volume and Extend Volume function to resize allocated partitions. However, because of their restrictions, you can't extend C drive by shrinking D.

Shrink Volume can convert part of unused space to Unallocated space, but it can only make Unallocated on the right side of D. Extend Volume can only combine Unallocated space to the left adjacent partition. This is the reason why Extend Volume greyed out for C: and E: drive after shrinking D.

Thus, if you insist on using Windows built-in Disk Management tool, you have to delete partition D, then all its disk space will be converted to Unallocated, which is behind C drive, so Extend Volume is enabled.

In most of servers, partition D is used for programs, exchange or other Windows services, so you cannot delete it.

However, if you can delete the adjacent D, it is very easy to expand C drive.

Steps to extend C drive via Server 2012 Disk Management:

  1. Press Windows and X on keyboard, click Disk Management from the list.
  2. Right click drive D: and select Delete Volume.
  3. Right click C: drive and select Extend Volume.
  4. Simply click Next till Finish in the pop-up Extend Volume Wizard window.

Extend Volume Wizard

2. Extend partition C by shrinking D

This method is used when there is plenty of unused space in the adjacent partition.

Obviously, it is not a good idea to enlarge volume C by deleting D. NIUBI Partition Editor can shrink D and make Unallocated space on either side. Unallocated space can be added into C drive, no matter it is adjacent or not. By this method, Operating System, program, Windows services and associated settings keep the same with before. There is no difference except partition size changed.

Download NIUBI Partition Editor and you'll see all disk partitions with structure and other information. There is C, D, E and system reserved partition in Disk 0.

NPE Server

Steps to extend partition C in Windows Server 2012 with NIUBI:

Step 1: Right click drive D: and select "Resize/Move Volume", drag left border towards right in the pop-up window. (or enter an amount manually)

Shrink D

Then part of unused space is converted to Unallocated on the left side of D.

Drive D shrank

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

Extend C drive

Then Unallocated space is combined to C drive.

C drive extended

Step 3: Click Apply on top left to execute, done.

NIUBI is designed to work in its virtual mode, the operations you do will be listed as pending on bottom left, and real disk partitions won't be modified until click Apply to confirm.

3. Extend volume C from nonadjacent E

This method is used when there is not plenty of unused space in the adjacent partition.

In some servers, there may be not plenty of unused space in the contiguous partition D, then you can shrink the non-adjacent partition E. Before adding Unallocated space to C drive, there is an additional step to move Unallocated space from right side of D to the left.

To do this, right click partition D: and select "Resize/Move Volume", drag middle position towards right in the pop-up window.

Move drive D

Video guide how to extend C: drive in Windows Server 2012 by shrinking other partitions:

Video guide

4. Enlarge C drive with other disk

This method is used when there is no available unused space inside a disk.

In few servers, there is no other partition or not plenty of unused space in all other partitions. No partitioning software can expand C drive by adding space from another separated disk. In this case, you can clone this disk to a larger one with NIUBI Partition Editor. Extra disk space will be shown as Unallocated on the end of disk, then you can extend C drive and other partitions with this Unallocated space.

Watch the video how to extend volume C in Windows Server 2012 with other disk:

Video guide

Better than other tools, NIUBI Partition Editor has powerful data protection technologies and fast file moving algorithm.