[Solved]: Lost Disk Space After Defrag in Windows 10

Have you experienced lost disk space after defrag? This article will use a professional third-party software to show you how to increase disk space.


By Dervish / Updated on May 12, 2023

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Lost disk space after defrag in Windows 10


Yesterday, I decided to defrag my old laptop (running Windows 10). However, I found that I lost disk space after defragmentation. My hard disk space was reduced from 206.2G to 193.8G. So I checked the problem we encountered online and dealt with it according to the solutions given on the internet (deleting the system restore point, deleting the “shadow copy”, etc.), but the situation has not changed. I have browsed many websites, but I have never found a solution to this problem. Now I just want to know how to increase my disk space? Because I don’t want to shrink it anymore. I hope someone can help me. Thanks in advance!”

- Question from CCleaner Community Forums

How to save the lost disk space after defrag

“Lost disk space after schedule defrag” is a common phenomenon, and there is no definite answer to this question at present. But we can still solve it in another way. That is, to increase the disk space to make up for the part of the disk space you lost.

To increase disk space, we need the help of a third-party tool, AOMEI Partition Assistant Standard. It breaks through the limitations of Disk Management and has more comprehensive functions. It provides some methods to increase the disk space, not only can fill the lost part, but also can extend partitions, even the BitLocker partition. So that you do not have the worry of insufficient disk space.

Don’t hesitate, download this free partition manager quickly to make up for the lost space.

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▶ Solution 1. Extend disk space via resize partition

For example, if your C drive lost disk space after defragmentation. This method is to add the unallocated space adjacent to the C drive to the C drive. It only takes three steps to complete.

Step 1. On the main interface, you can see all the hard disks on the computer and the partitions on different hard disks. Then right-click your C drive and select Resize/Move Partition.

Step 2. In this step, you can drag this button to increase the space required by the system drive and click OK.

Step 3. You can preview that all the unallocated space on the right has been added to the C drive. Don’t forget to click Apply to generate the operation.

▶ Solution 2. Extend disk space by merging partition

What you need to pay attention to is when using the first method, there must be adjacent unallocated space on the left or right sides of the target partition. If there is no adjacent unallocated space, you can also use Merge Partition to extend the space.

Step 1. Same as method one, right-click C drive and select AdvancedMerge Partition.

Step 2. Select a non-adjacent unallocated space or an adjacent partition (if this partition has data, then the data in the partition will be merged into the C drive), and click OK.

Step 3. Click Apply, you will see the C drive has been extended.

How to extend disk space with Allocate Free Space

The first two methods are more common methods, and the third method uses the advanced features of AOMEI Partition Assistant Professional. It is simpler than Method 1 and Method 2. There is no need for adjacent unallocated space, and no need to merge other partitions with the C drive too. Just need to allocate the extra free space of other partitions to the C drive. You can download the demo version for a free trial first.

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The specific steps are as follows:

Step 1. In the main interface of AOMEI Partition Assistant Pro, select the target partition and choose “Allocate Free Space”.

Step 2. Then type in the size of the free space which you want to cut from the D drive and this free space will be directly added into the C drive.

Step 3. You can take a preview of the operation result before confirming start. Click “Apply” to execute this operation.

Final words

Did you see? Extend partition is a way to solve the “loss of disk space after defrag” from the side. And AOMEI Partition Assistant can help you achieve this goal in a simple way. Why don't you try it? In addition to Allocate Free Space from one partition to another, AOMEI Partition Assistant Professional can also move installed programs from the C drive to another drive to free up space. Other more functions are waiting for you to unlock.

Dervish · Staff Editor
Dervish is an English editor of AOMEI Technology; He is delicated to offering users easy and effecitve solutions for issuses related to disks and partitoins. In his spare time, he enjoy wathcning films, playing footable, traveling and so on.