How to shrink C drive with Windows 10 Extend Volume function

Updated on: May 17, 2019

This article introduces how to shrink C drive with Windows 10 Shrink Volume function in Disk Management, and better method to shrink partition with partition editor software.

When installing Windows 10 to a new hard disk, if you forgot to create volumes, all disk space will be used by C drive except the small reserved partitions. As we know, it is not a good idea to use such big C drive and put everything into it. Instead, you'd better create separate volumes for applications and data. Then is there a way to decrease C drive and create more volumes without reinstalling? Yes, in this article I'll introduce how to shrink C drive volume with Windows native and third party tools.

Shrink volume in Windows 10 Disk Management

The same with Windows 7, Windows 10 Disk Management tool has Shrink Volume function, which can decrease system and data volumes without losing data and on the fly. However, you can't shrink C drive in some situations.

Steps to shrink C drive with Windows 10 DM:

Step 1: Press Windows and X on the keyboard and select Disk Management from the list.

Step 2: Right click C drive and select Shrink Volume

Shrink volume

Step 3: Enter the amount of space and then click Shrink to execute.

Enter space

In a short time, C drive is shrank. Windows 10 Shrink Volume function can only make Unallocated space on the right side.

C drive shrank

Cannot shrink C drive in some situation

Disk Management is easy to use, but you may encounter error when shrinking C drive volume.

Shrink volume

In the Shrink window, Disk Management give you maximum available space by default. Generally speaking, you'd better enter the amount manually according to your C drive size. (1024MB=1GB)

When I testing, I did click Shrink with default maximum amount of space. After clicking Shrink, I got the error message: "There is not enough space available on the disk(s) to complete this operation."

Shrink error

Another common issue: there is plenty of free space in C drive but Disk Management only allow shrinking with little space.

Shrink C drive

As you see in my test computer, there is 47.88GB unused space in C drive, but Disk Management give me maximum 38226 (37.33GB).

Have you noticed the tip on the bottom of the Shrink Window: "You cannot shrink a volume beyond the point where any unmovable files are located."

For example: C drive is made up of 4 blocks. If the unmovable files are located in block 3, you cannot shrink C drive to block 2 or 1 even though there is free space.

Cannot shrink

This is the reason why I got error message when using the default maximum space. "Unmovable" files include Paging file and the very large file such as hibernation, system backup files. If there are such files in C drive, you can only shrink a little space.

Shrink volume with partition editor

Comparing to Windows Disk Management, NIUBI Partition Editor has many advantages such as:

To shrink C drive volume in Windows 10, you just need to click and drag on the disk map. Besides shrinking partition, it also helps you extend, merge, copy, convert, defrag, wipe, hide partition, etc.

How to shrink partition in Windows 10 with NIUBI:

Download NIUBI Partition Editor, right click the partition that you want to shrink and select "Resize/Move Volume".

Option 1: If you drag left border towards right in the pop-up window,

Shrink D

Unallocated space will be produced on the left side.

Shrink D rightwards

Option 2: If you drag right border towards left in the pop-up window,

Shrink D

Unallocated space will be produced on the right side.

Shrink D lefttwards

This software work in virtual mode to avoid mistake, to shrink physical disk partition, click Apply on top left to execute.

In Summary

To shrink partition in Windows 10 (either system or data partitions), the build-in Disk Management tool is one of the choices, but it has limitations including:

  1. Only support NTFS partition, FAT32 and other types of partitions can't be shrank.
  2. It can only make Unallocated space on the right side.
  3. Can only shrink little space if there are some unmovable files.
  4. Cannot shrink even 1MB is some special situations.

NIUBI Partition Editor is better choice. Besides shrinking and extending disk drive, it can do many other operations.