Windows Server 2016 C drive is running out of space

Published on: November 16, 2019

This article introduces what to do when system partition C drive is running out of space in Windows Server 2016.

Many administrator encountered the problem that system C: drive is running out of space in Windows 2016 server. In that case, if you contact server OEM manufacturers, they'll tell you to back up everything, delete all partitions, recreate partitions and restore everything. It sounds reasonable, but nobody likes do like that, because it costs such a long time. This article introduces easy and fast way to solve this annoying problem.

Step 1 - free up disk space with Disk Cleanup

When system partition C runs out of space in Windows Server 2016, the first thing is cleaning up disk to get some free space. Even if you cannot get large amount of free space, at least server could keep running in the right way. To help free up disk space, Server 2016 has native Disk Cleanup utility, which is able to remove most of common junk and unnecessary files safely.

How to clean up system partition C in Windows Server 2016:

  1. Press Windows and R together on the keyboard to open Run, type cleanmgr and press Enter.
  2. Select C: drive in the drop-down box and click OK.
  3. Wait Disk Cleanup to scan junk files and calculate space usage.
  4. Click the check-boxes of the files that you want to delete and click OK.
  5. Click Delete Files in the pop-up window to confirm and start deleting
  6. (Optional) Repeat to delete file system files.

If you did not free up disk space before, you may get several GBs of free space in C drive. However, you'd better continue Step 3 even if you get over 10GB free space, because these space may be eaten up quickly by new generated junk files.

Select files

Step 2 - additional methods to reclaim disk space (optional)

If you want to fight for more free space, there are addition 4 methods to help you.

1. Reset Page File

Page file uses part of disk space as virtual RAM and it is located in C drive by default. You can change it to other partition when C drive is running out of disk space.


  1. Press Windows and R to open Run, type sysdm.cpl ,3 and press Enter.
  2. Click Settings under Performance on top of System Properties window.
  3. In the Performance Options window, switch to Advanced tab and click Change below Virtual memory.
  4. Uncheck Automatically manage paging file, then click C: drive > No paging file > Set. And then click D or other drive > Custom size > Enter an amount > Set. Click OK to confirm. (It may requires reboot to take affect.)

Rest Page File

2. Delete Shadow Copies

If you enabled Shadow Copy, you can delete the previous copes.

  1. Open Window File Explorer
  2. Right click C drive > click Properties > switch to Shadow Copies.
  3. Select the previous copies and click Delete Now.


Delete shadow copies

3. Decrease Recycle Bin

All files that deleted by pressing DEL without SHIFT key will be thrown to Recycle Bin, where you can revert these files to original location manually if you deleted them by mistake. Recycle Bin use part of space of C drive by default, so more files in Recycle Bin means less free space in C drive.

You can decrease the size and change the location of Recycle Bin to other larger partition.

  1. Right click Recycle Bin.
  2. Select the drive for Recycle Bin.
  3. Select Customer size and enter an amount, click OK to confirm.

Reset Recycle Bin

4. Uninstall programs

Press Windows and X on the keyboard > Programs and Features, uninstall the programs that you no longer need.

Step 3 - move free space from other partitions

The most important step to fix C drive out of space issue in Windows Server 2016 is moving more free space from other partitions.

In most cases, there is at least one data partition on the same disk. You can shrink it with partition editor software, then part of free space will be converted to Unallocated. After merging Unallocated space to C drive, it will be converted to part of free space again. By this method, you'll get much more free space for C drive, Operating System, programs and everything else keep the same with before.

Download NIUBI Partition Editor and follow the steps in the video to add more free space to C drive:

Video guide