How to Allocate More Space to C Drive in Windows 10/11

by John, Updated on: October 23, 2022

Disk partitions are allocated while installing Operating System or by computer manufacturers. Many people ask whether it's possible to reallocate disk space without losing data. In this article, I'll introduce how to allocate more space to C drive in Windows 10/11 without losing programs and data. To allocate free space to C drive in Windows 10/11 computer from other partition, you may use native Disk Management tool or third party software. Selecting corresponding tool and method according to your own disk partition configuration.

Allocate space to C drive in Windows 10/11 without software

The same with previous Windows 7, Windows 10/11 has built-in Disk Management tool . It is able to create, delete, format, shrink and extend partitions. Some people tried to shrink partition D/E and got Unallocated space but they cannot add Unallocated space to C drive. Because Disk Management can only extend a partition when there is contiguous Unallocated space on the right. If you shrink D drive and any other volume with Disk Management, Unallocated space is always  nonadjacent to C drive, therefore, Extend Volume is disabled for C drive.

To allocate unused space to C drive in Windows 10/11, if you don't want to use any software, you must delete D (or E) drive to get contiguous Unallocated space. In addition, this adjacent partition must be the same  Primary with C drive. If D is Logical drive, Disk Management cannot help you in any way.

Extend Volume greyed

How to allocate space to C drive in Windows 10/11 with Disk Management:

  1. Press Windows + X on your keyboard and select Disk Management.
  2. Right click drive D and select Delete Volume.
  3. Right click drive C and select Extend Volume, click Next in the pop-up window.
  4. Follow up the Extend Volume Wizard via several clicks.
  • In Windows 7, press Windows + R, input diskmgmt.msc and press Enter to open Disk Management.
  • You'll lose data if you forget to transfer files before deleting D.

Allocate free space to C drive in Windows 10/11 from D drive

If you want to allocated free space to C drive in Windows 10/11 without deleting partition, third party software is needed. Better than Windows Disk Management, NIUBI Partition Editor can make Unallocated space on either left or right side when shrinking a partition. It can add Unallocated space to either contiguous and any nonadjacent partition on the same disk. To do this, you just need to drag and drop on the disk map. To Windows 11/10/8/7/Vista/XP home computer users, there's free edition. Download

How to allocate more space to C drive in Windows 11/10/8/7 with NIUBI:

Step:1 Right click the adjacent partition D and select "Resize/Move Volume", drag left border towards right in the pop-up window.

Shrink D

Then D drive is shrunk and Unallocated space is made on the left.

Shrink D rightwards

Step:2 Right click partition C and select "Resize/Move Volume" again, drag right border towards right.

Extend C drive

Then Unallocated space is allocated to C drive.

Extend volume C

This software is designed to work in virtual mode, to reallocate real disk partitions, remember to click Apply on top left to confirm and execute.

Allocate more space to C drive in Windows 10/11 from nonadjacent volume

If there is not enough free space in the adjacent drive D, you can allocate free space to C drive from any nonadjacent partition on the same disk. Follow the steps below:

Step:1 Right click drive E and select "Resize/Move Volume", drag left border towards right to shrink it and make Unallocated space on the left side.

Step:2 Right click drive D and select "Resize/Move Volume", drag middle of D drive towards right in the pop-up window. Then, Unallocated space will be moved to the other side.

Move drive D

Step:3 Right click drive C and select "Resize/Move Volume" again, drag right border rightwards to combine Unallocated space.

Reallocate C drive space with another disk by cloning

If there is no other volume or not enough free space on the same disk, the method above is invalid. Because the size of a disk is fixed and no software can move free space from a different disk. In that case, you can  clone disk to a larger one and repartition drive with extra disk space. Follow the steps in the video. Besides allocating free space to C drive in Windows 11/10/8/7/Vista/XP, NIUBI Partition Editor helps you do many other operations such as merge, move, convert, hide, defrag, wipe, scan bad sectors.

Download