Extend C drive

Extend C drive with Unallocated space in Windows 10?

The same with previous Windows Operating System, low disk space issue is also very common in Windows 10. After running Windows 10 for a certain time, C drive runs out of space and becomes full. In this situation, you can extend C drive with Unallocated space or free space in other volumes. In this article, I’ll introduce how to extend C drive with Unallocated space in Windows 10. To do this, you may use Windows native Disk Management or third party partition software.

Add Unallocated to C

Extend C drive with adjacent Unallocated space

The built-in Extend Volume function in Windows 10 Disk Management can used to extend C drive, however, there must be adjacent Unallocated space on the right side, otherwise, Extend Volume is disabled for C drive. Steps:

  1. Right click volume D and select Extend Volume.Extend volume
  2. Extend Volume Wizard will be opened, simply click Next to continue.Extend volume wizard
  3. Select available disk and space, click Next to continue.Select space
  4. Click Finish to confirm and start.Extending complete

If the Unallocated space is on the left side or nonadjacent to C drive, Windows Disk Management cannot help you. In these configuration, you need professional partition software.

Extend C drive with nonadjacent Unallocated space

As the best partition software for Windows laptop and desktop, NIUBI Partition Editor provides basic partition management to create, delete, format partition, change drive letter, etc. Advanced management to resize/move existing partition without data loss, copy, hide, set active, convert, defrag, check partition and much more.

To resize and extend partition, you just need to drag and drop on the disk map.

Download NIUBI Partition Editor, the right side of the main interface is very similar with Disk Management. As you see, there is 20GB Unallocated space behind drive D, we can move it to behind C drive.

Main interface

Right click drive D and select Resize/Move Volume, drag the middle position towards the right.

Move D

Drive D is moved to the right and Unallocated space is moved to the left at the same time.

Unallocated space moved

Now, we can extend C drive with this Unallocated space:

Right click C drive and select Resize/Move Volume again, in the pop-up window, drag the right border rightwards.

Extend C drive

Unallocated space is combined into C drive. Click Apply on top left to execute.

Unallocated space merged

In Summary

Windows 10 has the ability to resize partitioned drives with Shrink and Extend Volume functionalities, but they are very limited. Unallocated space that shrank from drive D is not adjacent to C drive, so you cannot extend C drive with this space. Applications are installed to drive D, so you cannot delete this drive to get adjacent Unallocated space. That is to say, Windows 10 Disk Management is useless in most conditions.

As the safest and fastest partitioning software, NIUBI Partition Edition can extend C drive with Unallocated space no matter it is adjacent or not. Furthermore, free space inside of any other drives in the same disk can be transferred to C drive, too.

Download NIUBI Partition Editor and follow the steps in the video to extend C drive with free space in Windows 10: