C drive full

C drive full or out of space on Windows Server 2019 – solution

The same with previous versions, Windows Server 2019 C drive runs out of disk space, too. When C drive is running out of space, you’ll suffer from server performance down. Furthermore, the server could stuck or restart unexpectedly if C drive is getting full, so you’d better solve this problem as fast as possible before C drive is full. In this article, I’ll show you complete solution how to fix C drive out of space in Windows Server 2019.

Symptom of C drive full

When you open File Explorer, C drive is shown as red instead of the default blue bar. It is to alert server administrator the urgent situation.

C drive out of space

If C drive is almost full in Server 2019, you’ll see a bubble notification of Low Disk Storage on bottom right corner.

Why C drive is getting full

There is small probability of system error that cause calculating disk space incorrectly. In most of the situations, C drive full is caused by files filling up.

  • Windows produce junk files in C drive every day, including Temp, Cache, Logs, Thumbnails, Downloads, Internet files, etc.
  • Default installation path of all programs are set to C drive. The more programs installed, the less free space in C drive.
  • Many programs output files to C drive automatically if you do not change the default settings. Some programs produce very large files.
  • To install some new features and reduce security risk, Windows download and install Updates frequently.

Solution of C drive out of space

To completely solve C drive full issue on Windows Server 2019, you should finish 3 steps:

  1. Free up disk space – the aim is to reclaim disk space by clearing up junking files, so the server could back to the right way.
  2. Increase C drive space – the aim is to expand C drive to larger size, so there will be plenty of free space in C drive.
  3. Change server settings – the aim is to transfer and delete new generated files.

Freeing up disk space is useful, but it cannot reclaim large amount of free space, especially when C drive is created small, so you should expand C drive as large as possible. If you do not change settings and clean up new generated junk files regularly, the free disk space will be eaten up sooner or later, so every step is indispensable.

Free up disk space

Windows Server 2019 provides built-in Disk Cleanup utility to free up disk space. It runs fast and is able to delete many types of junk files, steps:

  1. Press Windows and R on keyboard, type cleanmgr and press OK.Run disk cleanup
  2. Select C drive and click OK.Select drive
  3. Click the check-box in front of the files that you want to clear up. If you don’t know what files are included, click each option and you’ll see its description.

Select files

Select files

Click OK and Disk Cleanup will begin to clear up junk files.

Cleaning up

My test server is new installed, so there are few junk files to clean up. To the servers that are running for a long time but never freeing up disk space, you may reclaim over 10 GigaBytes disk space.

More about freeing up disk space in Windows Server 2019.

Increase C drive space

Download NIUBI Partition Editor and you’ll see all connected storage device. In my test server, drive D is almost empty, so I can transfer more free space to increase C drive.

Step 1: Right click drive D and select Resize/Move Volume.

NIUBI Main window

In the pop-up window, drag left border rightwards to shrink it.

Shrink drive D

Free space is taken out from D and displays as Unallocated behind C drive.

Drive D shrank

Step 2: Right click drive C and select Resize/Move Volume again, drag the right border rightwards in the pop-up window.

Extend C drive

Unallocated space is added into C drive, which is part of free space in drive D originally.

C drive extended


  • All operations you do will be listed as pending on bottom left, you need to click Apply on top left to execute the modifications.
  • The pending operations with  can be done in Windows without server interruption.

Change server settings

As I said above, if you do not change server settings, the free space will be exhausted by new produced files. The following options are not all but important.

1. Save files to new location

Better than previous Windows Servers, in Server 2019 you can change the default save locations for apps, documents, music, pictures, and videos to other place, so these types of new files will be saved to your specified partitions.

  1. Right click Windows on bottom left corner of the screen and click Settings.
  2. Click System Storage.
  3. Under “More storage settings,” click Change where new content is saved.
  4. Click the drop-down menu and select new location.

2. Change output path

All programs are installed to C drive by default and many of them output files there, too. The programs for videos and projects, as well as some Windows services produce many large files, so you’d better change the default output path manually to other location.

3. Turn on Storage Sense

Storage Sense is new added component, which can free up disk space automatically when C drive is running out of space in Windows Server 2019. It can delete temporary files and files in Recycle Bin and the Downloads folder. To enable Storage Sense:

  1. Open Settings
  2. Go to System > Storage
  3. Switch Off to On under Storage Sense on the right side.

4. Free up disk space regularly

This is not a visual settings, but an important memorable action in your mind, Storage Sense free up disk space automatically but only when C drive is getting full, and it can only clear up part of the junk files, so you should run standalone Disk Cleanup utility monthly.

Once again, the steps to free up disk space, expand C drive larger and change server settings are all important to fix C drive full in Windows Server 2019. Otherwise, C drive is running out of space and becomes full in near future.

Download NIUBI to expand C: