How to fix C drive running out of space in Windows Server 2012?

The annoying problem in Windows Server 2012 is about insufficient of disk space – the system C drive keeps running out of space, so there is not enough free space to install Windows Updates or applications. After opening Windows Explorer, you’ll find that C rive changed to be red. When C drive becomes full, Operating System will be stuck or even crash, in this situation originally you have to start from scratch to recreate disk partitions and spend a long time to restore everything. In this article, I’ll give easy method to fix C: drive running out of space in Server 2012 (R2).

C drive out of space

The risk of C drive running out of space

When C drive runs out of free space, you should try to fix as fast as possible, because it causes many problem such as:

  1. No free space to install critical Windows Updates.
  2. Some Windows services stop working.
  3. System stuck, reboot unexpectedly or crash.

So to solve this problem, the earlier the better.

Free up disk space

The first option to fix C drive running out of space is freeing up disk space. You may either use Windows Cleanup or 3rd-party optimization software, but I always recommend Windows built-in Disk Cleanup.

Note: different with previous edition, Disk Cleanup in Windows Server 2012 is disabled by default, you have to install Disk Cleanup before using.

Step 1: Click Server Manager on bottom left, click the 2nd option “Add roles and features“.

server manager

Step 2: Click Next till you see Features.

Add roles

Step 3: Click the check-box in front of “Desktop Experience” and click Next.

Select to install

Step 4: Within several minutes, the installation complete, click Close.

Install complete

Step 5: Restart the server to finish adding features.


Step 6: Open Windows Explorer, right click C drive and click Properties, and then click Disk Cleanup.

disk cleanup

Step 7: In next window, select the files you want to delete and click OK.

select files

Step 8: Redo step 7 to Clean up system files.

After these steps, you can get some free space. The C drive out of space problem can be solved temporarily. If you did not get large amount of free space, or C drive is created too small, you’d better continue the steps below to expand C drive, otherwise, C drive runs out of free space again in near future.

Expand C drive on Windows Server 2012

With server partition software, you can reallocate free space to C: drive. That is to say, extend C drive by taking free space from other volumes. NIUBI Partition Editor is such software, which helps you complete this task without losing data, everything keeps the same after resizing except partition size changed.

Steps to resize partition to fix C drive running out of space:

Step 1: Download NIUBI Partition Editor, right click D: drive and select “Resize/Move Volume“.

Drag to resize

Step 2: In the pop-up window, drag the left border rightwards to generate free Unallocated space.

Shrink volume

You may also input a value for the Unallocated space directly.

Drag to resize

Click OK and back to the main window, where you’ll see 20GB Unallocated space created behind C: drive.

Unallocated space

Step 3: Drag the right border rightwards to hold the Unallocated space.

Drag to resize

Hold unallocated space

Step 4: Click OK and back to the main window, where you’ll see C drive extended to 60GB by robbing 20GB free space from D. Press Apply on top left to execute, done!

Partition resized

Video guide to fix C drive out of space in fast way

Better than other tools, NIUBI Partition Editor integrated unique Roll-Back protection technology, which is able to roll back the server to the status before resizing automatically and rapidly, even if power failure or any other hardware issue occurred, so don’t worry about Operating System and data safety. Furthermore, it is 30% – 300% faster than ANY other tools, because of its unique file-moving algorithm.

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