Resize partition Win10

How to resize partition on Windows 10?

This article introduces how to resize disk partition for Windows 10 (32/64 bit) without losing data or reinstalling OS. Resize partition volume with native Disk Management and partition editor software.

C drive running out of space is very common, no matter you use desktop or laptop, SSD, mechanical disk or RAID arrays. But to many computer users, it is not an easy task to resize partition for Windows 10. In technical forums, many people ask similar questions such as: “is it possible to resize disk drive without reinstalling Windows 10, my c drive is full but there is plenty in D“, “Is it safe to resize my Windows 10 volumes, will it cause data damage?” In this article I’ll explain why allocated partition can be resized, and how to resize Windows 10 partition safely.

Resize partition Win10

How partition resizing works?

A partition (also called as drive or volume) is just part of entire hard disk and there could be many partitions in a disk. A disk partition is used to store variety of files, including system and data files. All files are organized by File System.

Disk drive

Take MBR style disk as example:

Operating System read the parameters in MBR and then it knows how many partitions in this disk, the start and end position of each partition. From DBR of each partition, Operating System gets the list of all files in this partition including name, create date, type and additional parameters of each file. From the parameters, Operating System can locate the data area. To change a file, Operating System simply modify the data area and then update the related parameters in DBR.

To resize a disk partition, it is much easier if it doesn’t require moving location of this partition. In this case, the partition tool just modify the parameters of start and end position of this volume. But if partition moving is required, it is much more complicated, besides updating partition position, the partition tool also move location and update parameters of all file in this volume, so it cost much longer time if there are large amount of files.

Which tool to resize disk partition?

There are two kinds of tools to resize volume on Windows 10: built-in Disk Management and 3rd-party partition software.

The advantage of Disk Management is born from Microsoft (actually provide by other company), both Shrink and Extend Volume feature can change partition size without rebooting, but meanwhile it has many limitations. It is far behind the professional partition management software.

How to resize partition in Windows 10 Disk Management:

Windows 10 Disk Management has NO “resize volume” functionality, partition resizing is realized by Shrink Volume and Extend Volume.

To shrink a volume:

  1. Right click Windows on bottom left corner and select Disk Management.
  2. Right click the partition and select Shrink Volume.
  3. In the pop-up window, enter the amount of space and then click Shrink to execute.

Input size

To extend a volume:

  1. Right click the drive with adjacent Unallocated space and select Extend Volume.
  2. Simply click Next in the pop-up Extend Volume Wizard window.
  3. Confirm the operation and click “Finish” to proceed.

To use Extend Volume, your disk partition configuration should meet all requirements below:

  • The drive you want to extend should be NTFS, FAT 32 and other types of partitions are not supported.
  • There must be adjacent Unallocated space on the right side of this drive.
  • In MBR style disk, Free space in Extended partition cannot be added to Primary partition, even if it is right adjacent.

If you want to extend C drive by shrinking D, it is impossible in Disk Management. Shrink Volume can only shrink a drive (such as D:) towards left and produce Unallocated space on the right side, but to extend C drive with Extend Volume, Unallocated space must be on the left side of D. This is the reason why many people feedback that Extend Volume is greyed out.

Extend Volume greyed out

As you see, Extend Volume is also disabled for E drive, because Unallocated space is on its left side.

Resize Window 10 volume with software

With professional partition software, both NTFS and FAT32 partition are supported. Unallocated space can be generated on either side when shrinking. You can extend a drive with Unallocated space or free space inside of any other volume in the same disk, no matter these space are adjacent or not.

Download NIUBI Partition Editor, you’ll see all disk partitions with structure and detailed info on the right, available operations to the highlighted disk or partition are listed on the left side.

Steps to resize Windows 10 partition with NIUBI:

Step 1 Right click D drive and select “Resize/Move Volume“.

Resize volume

Drag the left border rightwards to shrink it.

Shrink D

Unallocated space is generated on the left side. (If you drag the right border leftwards, Unallocated space will be produced on the right side of D.)

Unallocated space

Step 2 Right click C drive and select “Resize/Move Volume” again, drag the right border rightwards to combine the Unallocated space.

Drag to extend

C drive is extended to 94.65GB, click Apply to execute, done.

C drive extended

Tip This program is designed to work in virtual mode, you can click Undo to cancel the unwanted pending operations, real disk partitions won’t be modified until click Apply to confirm.

If there is not enough free space in volume D, you can get free space from any other nonadjacent volumes in the same disk, just need an additional step to move partition.

Video guide to resize Windows 10 disk partition

Tips NO partitioning software can extend a volume by taking free space from another separated hard disk. If there is not enough free space in all other partitions in the same disk, you can clone to another large disk with NIUBI, and then extend partition with extra disk space.

Pay attention to data safety while resizing partition

Data safety is most important but there is system boot failure or data loss risk if you use some unreliable partition software. Better than other tools, NIUBI Partition Editor provides unique 1 Second Rollback, Virtual Mode and Cancel-at-will technologies to ensure system and data intact. It also provide Hot-Resize technology to help resize disk partition without interruption, advanced file-moving algorithm to help resize partition much faster. Besides resizing partition on Windows 10, 8, 7, Vista and XP, it helps you do many other operations.