Windows Server 2012 C drive running out of space

By Lance, Updated on: December 20, 2019

This article introduces the complete solution how to fix C drive out of space on Windows Server 2012 R2 with ease.

C drive low disk space is common issue in Windows Server 2012 and even the latest Server 2019. You can create a very large C drive when building a new server, because hard disk is much cheaper and larger nowadays, it is common to use 500GB+ SSD or 1TB+ raid array for system disk.

But to the servers that have been running many years, it is not good idea to start over or waste a long time to restore from backup. It is important to keep server online and running smoothly. When system C drive is running out of space on Windows Server 2012 (R2), you'd better fix this issue as fast as possible. This article introduces an easy 3-step solution.

Step 1 - free up disk space (required)

When Windows 2012 server system C drive is running low on disk space or even becomes full, you'll suffer from performance down, server stuck or reboot unexpectedly. In this situation, the most important thing is getting some free space in a short time to keep server running in the right way.

To do this, you just need to run Windows built-in Disk Cleanup utility, which can remove common types of junk and unnecessary files. Of course there are third party software that can accomplish this task, or even "better", but in my opinion, Server 2012 Disk Cleanup is easy, safe and reliable.

Follow the steps to free up disk space in Windows Server 2012 with Disk Cleanup:

  1. Press Windows and R together on your keyboard, type cleanmgr and press Enter.
  2. Select C: drive in the drop-down list and click OK.
    Disk Cleanup
  3. Click the check-box in front of the files that you want to delete and then click OK to execute.
    Select files

If you receive error with message Windows cannot find 'cleanmgr', you need to install or enable Disk Cleanup on Server 2012 first.

Disk Cleanup can help you reclaim over 500MB to several GBs disk space, but it is not enough, because the free space will be eaten up quickly by new generated junk files. You'd better add more free space to C drive.

Step 2 - expand C drive (required)

If there are free space in any other data volumes on the same hard disk, you can transfer into C drive with server partition editor software.

There are many choices in the market, but you'd better back up first and run the safest tool, because some unreliable software could cause system boot failure or data loss.

Better than other tools, NIUBI Partition Editor has innovative powerful technologies to protect system and data safety, for example:

Download NIUBI Partition Editor and follow the steps in the video to expand C drive by taking free space from other volume:

Video guide

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

Step 3 - server optimization (optional)

The more free space you give to C drive, the less chance C drive running out of space in Windows 2012 server, but to solve this problem completely, you'd better consider the following options:

  1. Install new programs to a separated partition such as D.
  2. Change the output path of the programs that installed in C drive to other partitions.
  3. Run Disk Cleanup monthly to delete new generated junk files.

In Summary

When system C drive runs out of space on Windows Server 2012 R2, run Windows built-in Disk Cleanup utility to get some precious free space, so server could keep running without issue. Then extend C drive as large as possible. Finally, clear up unnecessary and junk files regularly.