How to shrink C drive in Windows Server 2016?

When installing Windows Server 2016, if you forget to edit partition, all disk space will be used. We know it is not a good idea to keep single C drive in a disk, putting everything into it. You’d better divide this hard disk into several drives. What to do if C drive occupied all disk space, reinstalling? No, you can shrink C drive directly. To do this, you may use either Windows built-in utility or 3rd-party software. Windows built-in Disk Management console integrates Shrink Volume to decrease partition size, keeping server online. However, in some conditions, it cannot shrink C drive, in that case, 3rd-party partitioning software is needed. In this article, I’ll introduces how to shrink C drive in Windows Server 2016 Disk Management and with server partition software.

Shrink C drive in Server 2016 Disk Management

Step 1: Right click Windows on bottom left and select Disk Management.

Open disk management

Step 2: Right click C drive and select Shrink Volume.

Shrink volume

Step 3: Enter the amount of space to shrink. (Default value is all available space – minimum size, this is not suggested)

Type amount

Click Shrink to proceed, C drive shrank in a short time.

C drive shrank

Why cannot shrink volume

In some conditions, you cannot shrink C drive, or can only shrink a little space. As the notification in step 3, “You cannot shrink a volume beyond the point where unmovable files are located.” What does it mean? For example, there are 4 blocks in C drive: 1, 2, 3 and 4, the unmovable files are located in block 3, you can only shrink C drive to 3, even if there is free space in 1 and 2. The unmovable files refer to page file, hibernation and other large files. If you encountered the problem Windows not allow you to shrink C drive, try server partition software instead.

Shrink C drive with partition software

With partition software from Partition Magic Server, you can easily shrink C drive even if there are unmovable files, because it is able to move the “unmovable” files to block 1 or 2

Steps to shrink C drive:

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

Shrink c

Step 2: In the pop-up window, drag either left or right border to shrink, if you drag right border leftwards, the Unallocated space will be created behind C drive.

Drag to shrink

Drag to shrink

Step 3: Press Apply on top left to execute.

C drive shrank

What to do after shrinking C

After shrinking, free space in C drive will be converted to Unallocated automatically. With Unallocated space you can create new volume, or extend other volumes if you want.

Create new volume

Step 1: Right click the Unallocated space, and select “Create Volume“.

Step 2: Click OK to use entire Unallocated space and all default settings, or do advanced operations:

  1. Add label (name) to the new volume.
  2. Select a drive letter
  3. Select file system
  4. Select cluster size
  5. If the hard disk is MBR, you can select create new volume as Logical or Primary here.
  6. Drag either border or input a value to specify partition size and location.

Create volume

Extend other drives

If you want to shrink C drive to extend other volume such as D, follow the steps:

Right click D and select “Resize/Move Volume“. In the pop up window, drag left border leftwards to hold the Unallocated space.

Drag to extend


Extend D

Click OK and back to the main window, click Apply on top left to execute.

D extended

If you want to shrink C to create new drive, do it under Server 2016 Disk Management. If you can only shrink little space because of the unmovable files, or want to expand other drives, run NIUBI Partition Editor.

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