How to increase C drive space in Windows Server 2016

by James, Updated on: July 19, 2022

C drive low disk space is common issue in Windows 2016 server. It can't be better if you can increase C drive space without wasting a long time to recreate partitions and restore everything. This article introduces detailed steps to increase C drive space in Windows Server 2016 with native Disk Management tool and safest partition software. Follow the steps of corresponding method according to your own disk partition configuration.

Increase C drive space in Windows Server 2016 without software

The same with previous version, Server 2016 built-in Disk Management tool has Shrink Volume and Extend Volume functions to help resize partition without losing data. However, you cannot extend C drive by decreasing D or other partition. If you don't want to use any third party software, you must delete D to get contiguous Unallocated space.

Even if you can delete D drive, your disk partition layout must meet the requirements below:

  1. D must be on the right of C drive and on the same disk.
  2. There's a third partition to save all files in D drive before deleting.
  3. D must be a Primary partition. (The same with system C drive)

How to increase C: drive space in Windows Server 2016 with Disk Management:

  1. Transfer all files in D: drive to other partition. (D drive is adjacent partition behind C drive)
  2. Press Windows + X together on the keyboard and click Disk Management in the list.
  3. Right click D:  drive and select Delete Volume, then its disk space will be converted to "Unallocated".
  4. Right click C: drive and select Extend Volume, follow up the pop-up "Extend Volume Wizard".

Better way to increase C drive space in Windows Server 2016

Obviously, it is not good idea to extend C drive by deleting other partition. To increase C drive free space in Windows 2016 server, it is better to shrink other volume, so you won't lose any partition. Operating System, programs and anything else keep the same with before (except partition size).

Third party software can shrink D drive and make Unallocated space on the left, then C drive can be extended easily. If you've shrunk D drive with Disk Management, or if you wan to get Unallocated space from a nonadjacent partition, these software can move partition and make Unallocated space next to C drive. 

While resizing server partition, there is potential system and partition damage risk, because all parameters of associated disk, partition and files must be modified correctly, files in some partition must be moved to new locations. Any slight error could cause system boot failure and data loss.

Better than other tools, NIUBI Partition Editor has powerful technologies to protect your system and data:

1. Increase C drive free space by shrinking D/E

Before starting, check if there's enough free space in other data volume on the same disk, if yes, follow the steps below.

How to increase C drive space in Windows Server 2016 without losing data:

  1. Download NIUBI Partition Editor, right click D: drive and select "Resize/Move Volume", enter an amount of space in the box of Unallocated space before, or drag left border towards right in the pop-up window. Then there will be Unallocated space made on the left.
  2. Right click C: drive and select Resize/Move Volume again, drag the right border towards right to combine this Unallocated space.
  3. Click Apply on top left to execute. (Any operations before this step only work in virtual mode.)

If you want to increase C drive by shrinking nonadjacent partition E, there's an additional step to move partition D towards right.

Video guide to increase C: drive size in Server 2016:

Video guide

2. Increase C drive space/size with another disk

If there's no other data partition or not enough free space on the same disk, the method above is invalid. No software can add space to C drive from a separate disk, because the size of a physical disk is fixed. In this situation, there are still 2 ways to increase C drive space for Windows 2016 server.

If there's no other partition on the system disk, you need to copy this disk to a larger one, and then expand C drive with additional disk space, follow the steps in the video:

Video guide

If there's data partition on the same disk but has not enough free space, besides copying entire disk to a larger one, you may move this data partition to another disk, then delete it and add its space to C drive.

3. Extend Server 2016 C drive in VMware/Hyper-V/RAID

If you want to increase C drive space in Windows Server 2016 with RAID 1/5/6/10 (any type and any brand), do not break RAID array, simply follow the methods above. If you run Windows Server 2016 as virtual machine in VMware/Hyper-V, just install NIUBI to the virtual server.

Better than physical disk, virtual disk in VMware and Hyper-V can be extended without losing data, so it's much easier to solve this problem. If there's no available free space on the same disk, follow the steps to expand virtual disk in VMware or Hyper-V. Additional space will be shown as Unallocated at the end, follow the steps to move and merge Unallocated space to C drive.

In Summary

To increase C drive space in Windows Server 2016/2019/2022 and previous Server 2003/2008/2012, native Disk Management can do little help. You'd better back up first and run reliable partition software. As the safest tool, NIUBI Partition Editor helps increase C drive free space without losing data, no matter how your disk partition is configured. It also helps do many other disk and partition management operations.