How to resize/extend system partition in Windows Server 2016

The same with previous Windows editions, in Windows Server 2016, system partition is running out of free space and becomes full. In this situation, nobody likes to waste a long time to back up everything, recreate partitions and restore. Many people ask whether it’s possible to resize partition and extend system drive in Windows Server 2016. The answer is definitely yes. In this article I’ll introduce 2 ways to extend Server 2016 system partition without losing data.

About System partition

Many people think system partition is the one that runs Windows Operating System, but it is not.

System partition 2016

From the screenshot, the partition that marked as System is a System Reserved partition. C drive is marked as Boot partition. No matter you want to extend system volume or extend system reserved partition in Windows 2016 server, it is possible. However, to avoid misunderstanding, system partition here means C drive, the same with other people.

Benefits to resize Server 2016 partition

In one word: fast. As I said above, if you back up everything, recreate all partitions, finally restore and verify data, it costs such a long time. Instead, you can shrink a large partition to create new volume or expand another one. After shrinking a partition, part of free space will be released and converted to Unallocated space. This type of space can be added to any other volume on the same disk.

With a fast partition tool, you can extend Windows 2016 system partition within an hour, or even several minutes. After resizing and extending partition, Operating system, programs and anything else (except volume size) keeps exactly the same with before.

However, you still need to back up the server before any operations. There’s potential system and partition damage risk even with Windows native tool. A safe partition tool can significantly reduce the risk of damage.

How to resize system partition in Windows Server 2016

To extend system partition in Windows Server 2016, there are 2 types of tools – native Disk Management and third party software. I’ll introduce how to extend system drive with both tools. But before starting, there are several points you should know:

  1. You can only resize partition inside a disk, no tool can extend partition with free space on another separate disk.
  2. If you use any types of hardware RAID array, do not break array or do any operation to RAID controller. The steps are the same to resize partition on physical disk, RAID array or VMware/Hyper-V virtual disk.

Method 1 – Extend system drive with Disk Management

The same with previous Server 2012/2008, Windows Server 2016 has native Disk Management tool to help resize disk partition. However, it is useless in most cases, because it has many limitations such as:

  1. It can only shrink and extend NTFS partition, any other partitions are not supported.
  2. It can only shrink a partition from right to the left. In addition, it cannot shrink partition beyond the point where unmovable files are located.
  3. To extend a partition, there must be contiguous Unallocated space on the right. Otherwise, Extend Volume option is grayed out.

Note: if you want to extend system partition in Windows Server 2016 without any software, you must delete the volume behind C drive. In some servers, the contiguous partition is Logical. In that case, Disk Management cannot extend Server 2016 system drive even after deleting.

Steps to extend Server 2016 system partition without any software:

1. Press Windows + X keys to open Disk Management, right click the adjacent partition D (or E:) and select Delete Volume.

2. Right-click C drive and select “Extend Volume…

Extend volume

3. The Extend Volume Wizard will be launched, click Next to continue.

Extend wizard

4. In the pop-up window, select the available space and click Next.

Type value

5. Confirm the operation and click “Finish” to proceed.


In general, system partition C will be extended in a short time.

Some people feedback that they cannot extend Windows 2016 system partition after shrinking D. As I explained above, Disk Management can only shrink partition towards left and make Unallocated space on the right. As the screenshot below, after shrinking D drive, Unallocated space is nonadjacent to C drive, of course Extend Volume is grayed out. This is the reason why you must delete D to get adjacent Unallocated space.

Extend volume greyed out

If you encountered the same issue, follow the steps to move partition D rightwards and then extend C drive.

Method 2 – Extend system volume with partition software

With server partition software, you can extend system drive without deleting any partition. To shrink and extend partition, you just need to drag and drop on the disk map. There are many partition software for Server 2016, but you’d better back up in advance and run the safest software.

Better than other tools, NIUBI Partition Editor has Virtual Mode, Cancel-at-well and 1-Second Rollback technologies to protect your server system and data. In addition, it is much faster if files need to be moved when resizing partitions.

How to extend system partition in Windows Server 2016 without losing data:

Step 1. Download and install NIUBI Partition Editor, right click the contiguous volume D and select “Resize/Move Volume“.

Select Resize

Step 2: In the pop-up window, drag left border rightwards to shrink this partition.

Shrink d drive

Drag to shrink

Step 3: Right click system partition C and select “Resize/Move Volume” again. In the pop-up window, drag the right border rightwards to combine this Unallocated space.

Extend C drive

Extend C

Step 4: Click Apply on top left to execute, done.

C drive extended

If there is not plenty of free space in the adjacent drive D, you can get free space from other drives on the same disk. Follow the steps in the video to extend system partition in Windows 2016 server.

Besides shrinking and extending partition, NIUBI Partition Editor helps you do many other disk partition management operations.

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