Resize system partition in Windows Server 2012

Updated on: November 16, 2019

This article introduces how to resize system partition in Windows Server 2012 R2 without losing data. 3 ways to adjust size of system volume with detailed steps.

The most common disk issue in a server is that system partition C getting full. In most cases, there is other volume with plenty of free space in the same disk. Then is it possible to resize this volume to expand system partition without losing data? Yes, of course. You may adjust partition size with either native Disk Management tool or third party software.

Resize system volume in Server 2012 Disk Management

Disk Management is safe in most cases but it only works under restricted condition. Third party tool is much more powerful but there is system damage and data loss risk if you use some unreliable software.

Firstly, let's see how to resize and extend system partition in Windows Server 2012 Disk Management.

Press Windows and X on the keyboard, then click Disk Management from the list. When you right click the system partition C, Extend Volume is disabled. Before extending this partition, you need to delete or shrink other volume to get Unallocated space.

The serious restrictions of Disk Management include:

So, you cannot extend system partition by shrinking any other volumes. The only option is by deleting the adjacent drive (D:).

If you cannot delete D or there is no other partition in the same disk, Server 2012 Disk Management is useless.

Extend volume disabled

If you can delete the right contiguous partition (D:), right click C: drive and select Extend Volume, simply click Next in the pop-up Extend Volume Wizard window.

Resize system partition with drive D or E

Server partition software can shrink drive D and make Unallocated space on the left side, then you can resize system partition C with either tool. If you have shrunk D via Disk Management or there is not enough free space in the contiguous partition, you can shrink drive E and move Unallocated space next to C drive.

However, as I said in the beginning, there is potential data loss risk, so you'd better back up first and run safe partition software. Better that other tools, NIUBI Partition Editor has innovative technologies to protect data and save time.

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. Original C: drive is 40GB and D: is 70GB. To resize partitions, you just need to drag and drop on the disk map.

NPE Server

Steps to resize system partition C in Windows Server 2012:

Step 1: Right click the contiguous partition (D:) and select "Resize/Move Volume", drag left border towards right in the pop-up window to shrink it. (or enter an amount in the box Unallocated space before)

Shrink D

Then drive D is reduced and some Unallocated space is made on the left side.

Drive D shrank

Step 2: Right click system partition C: and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.

Extend C drive

Then C: drive is increased to 60GB.

C drive extended

Step 3: Click Apply on top left to take effect to real disk partition.

Watch the video how to resize system partition in Windows Server 2012 by shrinking other volumes:

Video guide

Adjust system partition size with other disk

A hard disk is physical unit and the size is fixed, so no partitioning software can extend system partition by adding space from another separated disk.

If there is no other partition or not plenty of free space in other partitions on the same disk, you can copy entire disk to a larger one and enlarge system partition (and other volumes) with extra disk space.

Follow the steps in the video to extend system volume in Windows Server 2012 with other disk:

Video guide

No matter how your disk partition is configured, there is a way to increase size of system partition with NIUBI Partition Editor. It supports any types of local and removable hard disk, any types of hardware RAID arrays, VMware and Hyper-V Guest virtual disk.

If you use any RAID arrays such as RAID 0/1/5, do not break array or do any operation to the RAID controller. There is no difference to resize physical or virtual disk partitions.