By Dervish / Last Updated September 26, 2021

Transfer free space from one drive to another for better management

We install operating system, system programs, applications and personal data on hard drive partition. If there is not enough space or memory for system drive, one cannot install new applications on this partition. Existing applications on C drive may also not work well. What’s worse, system running performance may be affected meanwhile. Likewise, if there is no enough disk space on data drive, such as partition D, E, F, one cannot store new data to this partition. Also, he cannot create new documents or files from this partition.

In cases, the hard drive partition of our computer is not rationally partitioned when we purchase it. For instance, the system drive is partitioned with 60GBs at first. After year’s use of the PC, it becomes red and prompts low disk space warning. Add free disk space from one drive to another is good to make full use of hard drive capacity. The redundant space in large partition won’t be wasted and the problem of lacking of storage in small drive can be solved, so why not?

How to transfer space from one drive to another in Windows 11/10/8/7?

Technically, there are several solutions to fix this issue since the theory is to increase one drive space by reducing another drive. To change the unreasonable partition layout, one can resize partition using Diskpart, the built-in tool of Windows. However, this is a roundabout way because no matter to shrink or extend partition, the unallocated space won’t be the location that you want it to be.

Diskpart extend volume

Disk Management is also a great tool in managing hard drive and its partitions. It has graphical user-interface that is suitable for user who has limited computer knowledge. If there is unallocated space adjacent to the partition you want to increase, just right click the partition and select “Extend Volume”. If not, one can delete the contiguous partition to make it as unallocated and then repeat above steps. It is good to backup files before formatting or deletion.

Extend Volume

Although Windows brings excellent tools, some users just wonder if there is a way out that allows us to allocated free space from one partition to another without formatting hard drive or any partitions.

Fortunately, the answer is positive. AOMEI Partition Assistant Professional provides a feature named “Allocate Free Space” can help us transfer free disk space from one drive to another directly, for example, move space from D to C drive in clicks in Windows PC. To perform this task in Windows Server, you can turn to the Server edition.

How to transfer space from D to C Windows 10 via professional manager?

1. Install and launch AOMEI Partition Assistant on the computer. Right click the partition you want to allocate from (partition D with free space) and select “Allocate Free Space”.

Allocate Free Space

2. In the pop-up window, it gives you option to specify the space size and destination partition. Select C drive from the given list.

Allocate From D To C

3. Here is a virtual outcome. Click “Apply” > “Proceed” to make it real.

Apply Allocate Free Space


  • Since the system drive is involved, a restart is required.

  • This applies to different partitions on the same physical hard drive. Drives on different hard drives cannot do this in this manner.

  • This version also supports command line operations, so you can resize or move a partition, etc, from Command Prompt.


Easy and fast, in three steps, the free space is magically transferred from the big drive to the smaller one. AOMEI Partition Assistant Professional is advanced edition and it has a Standard version that has less functions. With this basic tool, one can also give space from one drive to another to redistribute free storage.

Step1. Right click the partition with redundant space and select “Resize Partition” to generate an unallocated space on the hard drive. The location of the unallocated space does not matter.

Step2. Click “Apply”.

Step3. Right click the partition you want to increase and select “Merge Partitions”. In the pop up window, you are allowed to check both this partition and the unallocated space.

Step4. Click “Apply” to execute the pending operations.


Actually, when it comes to how to transfer space from one drive to another in Windows 10 or Windows 7, many countermeasures are workable. Nevertheless, to find out the easiest workaround and reduce the risk of losing data during the process is not that easy.

AOMEI Partition Assistant is capable of solving many other issues as well. For example, it is a Lexar USB drive format tool that can format other brands of USB sticks, too. If you installed SSD and want to move Windows 10 to new SSD, this software can do you a big favor in migrating OS to SSD and keeping files on HDD.