How to increase C: drive space in Windows Server 2012

by John, Updated on: March 15, 2022

When system partition C runs out of space, it costs such a long time if you recreate partitions and restore everything from backup, so many people want to increase C drive free space directly. Then is it possible to increase C drive space in Server 2012 (and R2) without losing data, if yes, which is the best tool to accomplish this task?

It is always suggested to back up first and run safe partitioning software. In this article, I'll introduce how to increase C drive space in Windows Server 2012 R2 easily and safely.

1. Increase C drive space in Server 2012 with native Disk Management

To increase C drive space in Server 2012 (R2) Disk Management, your disk partition configuration must meet the requirements including:

  1. C drive must be NTFS. (No problem to most of servers)
  2. There must be another partition on the right of C drive and on the same disk.
  3. The right contiguous drive (such as D:) must be Primary partition.
  4. There are no programs or Windows services installed in D drive, so you can delete it to get Unallocated space.

Although there is Shrink Volume function to help decrease partition size, but Unallocated space can only be made on the right side. As you see in my server, Extend Volume is disabled for both C: and E: drive after shrinking D. This is because Extend Volume cannot combine Unallocated space to the right contiguous volume or any nonadjacent partitions.

Extend volume disabled

How to increase C drive space with Server 2012 R2 Disk Management:

  1. Back up D or transfer all files in it to other place.
  2. Press Windows and X together on the keyboard and select Disk Management from the list.
  3. Right click D and select Delete Volume, then its disk space will be changed to Unallocated.
  4. Right click C and select Extend Volume, click Next till Finish in next pop-up windows.
  • D means the contiguous partition on the right of C drive, it is E in some servers.
  • If D is Logical drive, Disk Management cannot extend C drive even after deleting D.

2. Increase C drive free space in Server 2012 R2 with NIUBI

Obviously, Disk Management is not the best tool to help increase C drive free space in Windows 2012 Server. With server partition software, there are no such limitations. You can shrink a partition and make Unallocated space on either side. This Unallocated space can be combined to either contiguous partition or moved to any nonadjacent volumes.

As I said in the beginning, some unreliable software could damage system and data. Because disk partition parameters must be modified correctly, files must be moved to new locations, system associated files must be updated, too. Any slight error leads to boot failure and lose data.

Better than other tools, NIUBI Partition Editor has innovative 1 Second Rollback technology, which is able to automatically revert server to original status in a flash if any error is detected. In that case, server could back online rapidly without modification. In addition, it has other powerful technologies to protect data and save time, for example:

How to increase C: drive space in Windows Server 2012 r2 with NIUBI:

  1. Download this program, right click the contiguous partition D and select "Resize/Move Volume", drag left border towards right in the pop-up window (or enter an amount in the box behind Unallocated space before).
  2. Right click C: drive and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.
  3. Click Apply on the top left to confirm and execute.

If you use any type of hardware RAID array such as RAID 1/5/6/10 or run Server 2012 in VMware/Hyper-V, there's no difference, simply follow the steps in the video.

Video guide

In following cases, you need to move partition D before adding Unallocated space to C drive:

  • You've shrunk D drive with Disk Management, so Unallocated space was made on the right.
  • There's not enough free space in the contiguous partition D, so you have to shrink a nonadjacent drive on this disk.

3. Increase free space of system C drive with another disk

Some people feedback that there is no other partition on the system disk. In that case, no partitioning software can add free space to C drive from another separate disk. To solve this problem, you need to copy the entire disk to a larger one and increase size of C drive with extra disk space.

Follow the steps in the video to increase C drive space in Windows Server 2012 with another disk:

Video guide

In Summary

Windows native Disk Management cannot extend a partition by shrinking another one, so it is useless in most cases. You'd better back up the server and use safe software to resize partition. Because of the powerful technologies, NIUBI Partition Editor helps you increase space of C drive for Server 2012 fast and safely. Check your disk partition configuration and use the corresponding method above. Besides decrease and increase partition size, it helps you do many other disk and partition management operations.