How to shrink C drive partition in Windows 10

Updated on: November 16, 2019

This article introduces how to shrink C drive on Windows 10 (32/64 bit). Two ways to shrink C partition without reinstalling Operating System or losing data.

Shrink C drive via Windows 10 built-in tool

If you forget to edit and create partition when installing Windows 10 Operating System, C drive will occupy all available disk space. What to do in this situation? You can shrink C drive without reinstalling. To do this, Windows 10 has built-in Disk Management tool to help you without any software.

However, if you want to shrink partition C to extend D or other volumes, Disk Management cannot help you. I'll show you the method in next paragraph.

Steps to shrink C drive via Windows 10 Disk Management:

  1. Press Windows and R on your keyboard, type diskmgmt.msc and press Enter to open Disk Management.
  2. Right click C drive and select Shrink Volume.
  3. Click Shrink to use default maximum space, or enter an amount in MB (1024MB=1GB) manually. (As the screenshot above)

It is very fast to finish shrinking.

The scenarios can't shrink C partition

Shrink Volume works well in most situations, however, it has some limitations that may bring you into trouble.

It's better to run professional partition software such as NIUBI Partition Editor, which is free for home computer users. Unlike other free partition software, NIUBI is 100% clean without any bundled plugins.

Download and install, you'll see detailed disk partition info on the right and available operations on the left.

Main window

Shrink C volume to create new volume

Unlike Disk Management, you just need to drag and drop on the disk map with NIUBI. Better than Disk Management, you can generate Unallocated space on either side. Right click C drive and select "Resize/Move Volume" feature,

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

Resize partition C

Unallocated space is generated on the right side of C drive.

Shrink C

If you drag left border towards right in the pop-up window, Unallocated space will be produced on the left side of C drive.

To create new partition, simply right click the Unallocated space and select "Create Volume".

Shrink C to expand D drive

If partition D is on the left side of C drive, you should generate Unallocated space on the left side of C, but in most computers, D is on the right side of C.

Follow the step above to get Unallocated space, then right click drive D and select "Resize/Move Volume" again. Drag left border towards left to combine the Unallocated space:

Extend D

Click OK, partition D is extended to 59.77GB.

Unlike Disk Management that executes immediately, NIUBI Partition Editor is designed to work in virtual mode. The operations you do will be listed as pending on bottom left corner, real disk partitions won't be modified until click Apply to confirm.

To shrink C drive volume on Windows 10 (32 & 64 bit), NIUBI is much more powerful. It is also able to move, merge, copy, defrag, wipe, check, scan, convert partition, etc.