Increase space Windows 10

Increase C drive disk space on Windows 10

The disk space of all hard drives are allocated while installing Windows, but the free space may exhaust, especially for system C drive. In this situation, it can’t be better if you can increase disk space of C drive with free space in other partitions, so there will be plenty of free space in C drive again without reinstalling Operating System and tons of programs. Yes you can achieve, but you should take care of your data, because there is potential system damage and data loss risk.

In this article, I’ll show you how to increase disk space of C drive in Windows 10 without losing data.

Increase disk space without software

Windows 10 native Disk Management provides Shrink Volume and Extend Volume functionalities to change size of allocated partition on the fly.

  • Shrink Volume can decrease size of a partition and convert part of unused space of this partition to Unallocated, however, Unallocated space can only be generated on the right side of this partition.
  • Extend Volume can increase disk space of a partition when there is Unallocated space adjacent and on the right side.

Comparing with Windows XP, Windows 10 Disk Management has big improvement by adding these 2 functionalities. But, it is still not perfect to resize disk partition, because it has some serious restrictions:

  • When you decrease size of drive D with Shrink Volume, Unallocated space can only be produced on the right side of D, but to increase size of C drive with Extend Volume, Unallocated space must be on the left side of D. That is to say, you cannot extend C drive by shrinking D.
  • Both Shrink and Extend Volume support NTFS partition only.

So the only way to increase disk space in Windows 10 Disk Management is by deleting the adjacent partition. For example how to increase partition size of D:

  1. Transfer all files in drive E to other partition.
  2. Press Windows and X on keyboard and then click Disk Management.
  3. Right click drive E and select Delete Volume.
  4. Right click drive D and select Extend Volume.
  5. Click Next to complete the Extend Volume Wizard.
Increase space of D

Caution: If you want to increase disk space of C drive, but programs are installed in drive D or there are some Windows services running from D, do NOT delete D drive. Because these programs and services will become invalid after deleting even if you transfer files to other partition.

In this situation, you’d better increase C drive space with professional partitioning software.

Increase C drive space with software

Comparing with Windows 10 native Disk Management, NIUBI Partition Editor is much better choice, because:

  • You just need to drag and drop on the disk map to repartition hard drives.
  • Both NTFS and FAT32 partitions are supported.
  • Unallocated space can be produced on either side when shrinking a partition.
  • Unallocated space can be moved to either side if it is nonadjacent to the drive that you want to extend.
  • Besides resizing partition to optimize disk space, NIUBI can help you do many other management and optimization operations.

Then how to increase free space of C drive on Windows 10 with NIUBI? Follow the 2 steps below:

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

NIUBI main window

Drag left border rightwards in the pop-up window, or enter an amount behind “Unallocated space before” manually.

Shrink D drive

Click OK, drive D is shrank to 30GB and 20GB Unallocated space is produced on the left side of D. (If you drag right border leftwards, Unallocated space will be produced on the right side of D.)

Unallocated generated

Step 2 Right click C drive and select “Resize/Move Volume” again. In the pop-up window, drag the right border rightwards to combine the 20GB Unallocated space.

Extend C drive

C drive is extended to 50GB, click Apply on top left to execute, done.

C drive extended


  • To avoid mistake, this partition software is designed to work in virtual mode. The operations you do will be listed as pending for preview, real disk partition won’t be changed until you click Apply to confirm.
  • The pending operations with  can be done in Windows without rebooting.

Take care of your data

Different with read-only program (such as data recovery software) that just read the parameters from disk drives, partitioning software will modify the parameters of related disk and partition, sometimes it also move position of the files. So, there is system damage and data loss risk while resizing disk partition. You’d better back up and use safe partition software.

Better than other tools, NIUBI Partition Editor is integrated with unique 1 Second Rollback technology to protect system and data. If any software error or hardware issue (such as power outage) occur, it reverts the computer to original status automatically and rapidly like nothing happens. Furthermore, thanks to its unique file-moving algorithm, it is much faster. So if you want to shrink any data drives to increase disk space of C drive on Windows 10, 8, 7, Vista and XP. NIUBI is the right choice.

Download to try