How to shrink C drive volume Windows 10/8/7

by John, Updated on: April 13, 2021

When installing Windows to a hard disk, if you forgot to create more volumes, all disk space will be used by C drive except some 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 personal data. What to do if there are no data volumes on the system disk? Is there a way to shrink C drive and create more volumes without reinstalling Windows and programs". The answer is yes. In this article I'll introduce how to shrink C drive in Windows 10/8/7 with native Disk Management tool and best free partition software.

Shrink C drive with Windows 10/8/7 native Disk Management

The same with Windows 7/8, Windows 10 build-in Disk Management tool has Shrink Volume function, which can decrease C drive and data partition without losing data and on the fly. However, it can only shrink NTFS partition, there are more shortages and I'll explain in next section.

How to shrink C drive in Windows 10/8/7 using Disk Management tool:

Step 1: Press Windows and R together on the keyboard, type diskmgmt.msc and press Enter to open Disk Management. (Press Windows key and X in Windows 10)

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

If you don't enter an amount manually, the maximum available free space will be used by default.

If everything goes well, C drive will be shrunk in a short time.

C drive shrank

Why cannot shrink C drive partition beyond half

Windows Disk Management is easy to use, but it has 3 major shortages when shrinking a partition:

  1. It cannot change the start location, so it cannot shrink a volume towards right and make Unallocated space on the left side.
  2. As I mentioned above, it can only shrink NTFS partition. It is not an issue to system C drive, but many data partitions are formatted with FAT32 file system.
  3. It is unable to shrink C drive beyond the point where unmovable files are located.

As I said above, maximum available space is used by default. Many people click Shrink button directly without modifying the amount. It is very likely to receive the error message "There is not enough space available on the disk(s) to complete this operation."

After you running Shrink Volume function, available free space is calculated, but Windows Updates or other types of files are saved to this partition continuously. That means, the available space is changed. So, you'd better enter an smaller amount by yourself.

Shrink error

The most common issue when shrinking C drive partition is related to "unmovable" files.

Shrink C drive

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

There's a tip on the bottom of this dialog box: "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

"Unmovable" files include Paging file, Hibernation, system backup and other large files. Windows cannot move these files. This is the reason why many people feedback that they cannot shrink C drive beyond half or to 100GB.

How to shrink C drive beyond limit with free partition editor

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

To shrink C drive in Windows 10/8/7 laptop or desktop, you just need to click and drag on the disk map. It has free edition to Windows 10/8/7/Vista/XP home computer users.

How to shrink C drive partition in Windows 10/8/7 with NIUBI:

Download the free edition, right click the partition that you want to decrease 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 made 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 made on the right side.

Shrink D lefttwards

This software is designed to work in virtual mode to avoid mistake, to change real disk partition, remember to click Apply on top left to take effect. Follow the steps if you want to increase D drive or extend system reserved partition after shrinking C drive.

Besides shrinking partition, NIUBI Partition Editor helps you extend, merge, copy, move, convert, defrag, wipe, hide partition, scan bad sectors, etc.