How to Make Unallocated Space Contiguous to Extend Partition?

This article will tell how to make unallocated space contiguous to system partition or other partitions, then you can extend volume successfully.


By Emily / Updated on May 12, 2023

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Cannot extend C drive with unallocated space

“Recently, my computer always popped out the low disk space on C drive warning. So I shrunk D drive to get some unallocated space for extending C drive. But when I right click the C drive in Disk Management, the Extend Volume option is disabled. Search online it seems because the unallocated space is not adjacent to C drive. Anyone can tell how to make unallocated space contiguous to C drive in Windows? Thanks a lot!”

Extend Volume Grey Out

When you try to shrink D drive and extend C drive in Disk Management, you will find the unallocated space can only be used to expand D drive, not C. That’s because “Extend Volume” can only add unallocated space to the left contiguous partition in Disk Management. Moreover, “Shrink Volume” can only generate unallocated space on its right side.

That is to say, the generated unallocated space from shrinking a partition can only be added back to the donor partition, but cannot be merged into the non-adjacent partition or the right contiguous partition. So here comes the question: how to make unallocated space adjacent to the target partition for expanding it.

Can Disk Management make unallocated space contiguous to C drive?

Since extending or shrinking volume can be realized via Disk Management, so you might wonder if you can move the unallocated space to another location as well. Easy to verify: just right-click the unallocated space and see whether there is any choice involving moving the unallocated space. If you have done that, you must know there is not such an option.

Besides, you can also right-click the middle partition between the to-be-enlarged partition and unallocated space to check whether you are allowed to move it to the right side. Unluckily, no such option, either. So, it is self-evident that Disk Management cannot move unallocated space to make it contiguous to C drive. To realize this goal, a third-party partition manager will be required.

Easily make unallocated space contiguous to C drive with free partition software

To move nonadjacent unallocated space to be contiguous to the partition you want to extend (like C drive), you can switch to a free partition manager named AOMEI Partition Assistant Standard. This freeware is compatible with Windows 10/8/7/XP/Vista (either 32-bit or 64-bit). It makes up the limitations of Windows Disk Management and adds many other amazing disk partition features such as moving partition, cloning partition, checking partition for bad sectors, wiping partitions, etc.

The “Move Partition” feature is able to move the partition (ex: D drive) in the way of unallocated space and the to-be-extended partition (ex: C drive) to the right side, as a result, the unallocated space is contiguous to the target partition. It also provides you with a solution for "not being allowed to resize Bitlocker partition via Disk Management". Specific steps of how to make unallocated space contiguous are listed below:

Step 1. Download, install and launch this freeware on your Windows PC.

Download Freeware Win 10/8.1/8/7/XP
Secure Download

Step 2. Right-click the D drive and choose “Resize/Move Partition”.

Move Partition D

Step 3. In this window, drag the bar to the right side to move D drive after the unallocated space.

Drag To Right

Step 4. Now you can see the unallocated space is adjacent to C drive; right-click C drive and choose “Resize/Move Partition”.

Unallocated Space Behind C

Extend C Drive

Step 5. Drag the bar to the right side to move unallocated space to c drive and click “OK”.


Step 6. Back to the main interface, click “Apply” to commit the pending operation.


This is how to extend partition when there is non-contiguous unallocated space in Windows PC. If you are running the Windows Server operating system, you can try AOMEI Partition Assistant Server instead, which works on both Server and Windows.

Merge non-contiguous unallocated space into partition directly

Above we explain how to make unallocated space adjacent and then extend C drive via AOMEI Partition Assistant Standard. That requires you first move the unallocated space, and then add it to another partition. So, you might want to know whether you can merge non-adjacent unallocated space into partition directly. Yes, you can do that with the help of AOMEI Partition Assistant Standard. Its “Merge Partitions” function can make this job as easy as a pie.

Step 1. Right-click the partition you need to extend, and select "Advanced" > “Merge Partitions”.


Step 2. On this screen, tick the unallocated space and click “OK”.


Step 3. Click “Apply” to commit the pending operation.


See? This method involves fewer steps than making unallocated space contiguous first of all.


Now, you should have a clear understanding of how to make unallocated space contiguous to extend C drive or other partitions in Windows 10/8/7. The above methods are based on the condition where there is unallocated space on the same disk. What if there is no unallocated space? You can upgrade to Professional, which can directly allocate free space from one partition to another.

In addition to moving and merging unallocated space, AOMEI Partition Assistant software also helps do many other operations such as migrating OS to SSD, converting disk between MBR and GPT without deleting volumes, converting dynamic disk to basic without deleting volumes, etc.

Emily · Staff Editor
Emily is an English editor of AOMEI Technology; she has a great passion for providing easy solutions for people to tackle with all disk or partition management problems. In addition to writing articles about disk/partition management, she also edits great tutorials on how to back up and restore disk for data security. In her spare time, she loves to learn computer skill to improve herself or stay with her family to enjoy a good day.