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Lost Disk Space After Defragment | Get Space Back!

Lost disk space after defragmentation got you down? This guide offers solutions to reclaim your storage and troubleshoot this frustrating issue.

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Updated on May 09, 2024

Suppose you have a messy hard drive with files scattered everywhere, making it slow and frustrating to find what you need. In this situation, Defragmentation is like tidying up, aiming to make your computer run faster. However, you may find that lost disk space after defragment.

In this article, EaseUS will cover practical methods for fixing the space issue and introduce a powerful tool called EaseUS Partition Master. This software simplifies disk management, helping you maximize your hard drive. Ready to take back control? Let's dive in!

How to Fix Lost Disk Space After Defragment 

Lost disk space after Defragmentation shouldn't hold you back. Let's delve into practical solutions to reclaim your storage and regain control of your computer's performance.

Way 1: Resize Partition to Extend the Disk Space 

You can adjust the disk size and extend the partition to free up space and extend the disk. This may sound complicated. Don't worry. EaseUS Partition Master Free offers convenient and user-friendly features for adjusting disk size. This tool streamlines the complexity of disk management by clearly and concisely visualizing the hard drive and partitions. 

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Download it and learn how to regain the lost disk space below:

Step 1: Locate and select the target drive/partition

Launch EaseUS Partition Master and go to Partition Manager, select the target drive/partition to adjust its size, right-click on it and choose "Resize/Move".

choose the partition

Step 2: Resize or move the partition

1.To shrink the partition, simply drag one of its ends to free up unallocated space. Once done, click "OK". 

drag the mouse leftwards to resize partition

2. To extend the partition, make sure that there is unallocated space aside (if there isn't, follow the above steps to create some). In the same way, drag your mouse into the unallocated space. Click "OK".

drag the mouse leftwards to resize partition

3. To move a partition position, you need to leave unallocated space next to the target partition. If no, free up some unallocated space first.

Right-click the target partition, select "Reize/Move". Then drag the whole partition leftward or rightward to adjust its position. Click "OK" to confirm. 

drag the mouse leftwards to resize partition

Step 3: Confirm the result and apply changes

At this step, you will see the new disk partition information & diagram.

disk partition information after resizing

To save changes, click the "Execute Task" button and then "Apply".

apply changes to the partition

Key Features You Can Try

To better optimize your hard drive, download and install EaseUS Partition Master.

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Way 2. Free Up the Disk Space

After Defragmentation, various factors might still be hogging your disk space. The culprits can be duplicate files, hidden temporary files, and even old system restore points. It's time to clear them out and regain your storage!

Removing these unnecessary files is key to recovering your storage. There are three ways to clean temporary files and free up disk space. 

Option 1. Manual Cleanup:

  • Open Windows File Explorer.
  • Go to C: > Windows > Temp.
  • Delete the files within this folder.

Option 2. Automated Cleanup:

  • Go to Settings > System > Storage.
  • Click on "Temporary Files."
  • Choose your desired cleanup plan (e.g., every 14 days)

Option 3. Deep Clean to Free Up Disk Space

  • Delete Duplicate Files: Eliminate duplicate files—finally, free up even more space on your storage device. You can find and remove duplicate files using a third-party duplicate file finder. 
  • Uninstall Unused Programs: It would be beneficial to talk about programs that you are no longer using occasionally.
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Way 3. Extend the Disk With/Without the Unallocated Space

There may be instances when Defragmentation leaves you without free space on your system disk. In this case, EaseUS Partition Master Professional can assist you in increasing the size of your system drive with its "Allocate Space" feature. It allows you to transfer free space from other partitions safely, no matter if you have adjacent unallocated space:

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Option 1. Extend System C drive with unallocated space

  1. 1. Right-click on the System C: drive and select "Resize/Move".
  2. 2. Drag the system partition end into the unallocated space so to add it to the C: drive. And click "OK". 
  3. 3. Click "Execute Task" and "Apply" to execute the operations and extend the C drive.

Option 2. Extend System C drive without unallocated space

  1. 1. Right-click a big partition with enough free space on the system disk, select "Allocate Space".
  2. 2. Select the system drive at the Allocate Space From (*) To section, and drag the end of System C drive into the unallocated space. Click "OK" to confirm.
  3. 3. Click "Execute Task", it will list the pending operations, and click "Apply" to save the changes and extend the C drive.

0:00-0:26 Extend System Drive with Unallocated Space; 0:27-0:58 Extend System Drive without Unallocated Space.

Share this tool and effortless ways with Windows users that lost disk space after defragment:


Way 4. Allocate Disk Space With the 2nd drive 

Having multiple drives on your computer gives you more flexibility in optimizing disk space. If your system drive runs low, EaseUs Partition Master Professional lets you borrow space from a secondary drive to expand capacity. This means reallocating some of the secondary drive's storage to your system drive.

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Step 1. Launch EaseUS Partition Master and go to Partition Manager. Right-click the system C drive, select "Advanced", and click "Extend with 2nd Disk".

extend c drive with second disk 1

Step 2. After the software analyzes the status of the disk and lists the extended results, click "Customize Plan" to continue.

extend c drive with second disk 2

Step 3. Select the listed data to migrate, or click the location to select more, and then click Next to continue.

extend c drive with second disk 3

Step 4. Select which partition to column the expanded C partition after, for example, G, and click"Proceed".   

extend c drive with second disk 4

Why Lost Disk Space After Defragment 

You defragmented your hard drive, expecting more free space, but instead, you seem to have even less. How does that happen? Let's examine some potential culprits behind this puzzling phenomenon.

  • System Files: System files are essential for your computer to function correctly. During Defragmentation, these files might get moved or reorganized, occasionally leading to them taking up slightly more space than before.
  • Temporary Files: Defragmentation may produce temporary files to speed up the process. Because they aren't automatically deleted, these temporary files occasionally occupy valuable disk space.
  • File Fragmentation: While Defragmentation generally aims to make files more compact, it can sometimes have the opposite effect. In some instances, the process can lead to further file fragmentation, which might make them occupy a bit more space.
  • Recovery Points: System restore points and backup files are safety nets in case of problems. However, they also take up storage space, potentially contributing to lost space after Defragmentation, especially if you have a lot of them stored.


When disk space is lost after Defragmentation, it can be frustrating, but it can be resolved. This dedicated guide discusses different efficient solutions that can help you. Understanding the potential causes makes solving the problem easier.

In addition, maintenance tools like EaseUS Partition Master can be significantly simplified and made more intuitive. If you're struggling with limited disk space, feel free to give it a try. It can help you regain control of your computer's storage and optimize its performance.

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FAQs About Lost Disk Space After Defragment

Still have questions about lost disk space after Defragmentation? Let's dive into some common concerns:

1. Will defragmenting reduce disk space?

Typically, Defragmentation should not directly reduce your disk space. Its goal is to rearrange files for faster access, often resulting in slightly more free space. However, factors like temporary files, system file changes, and unexpected file fragmentation can sometimes lead to a slight increase in space usage after the process.

2. Can defragging a disk cause data loss?

Generally, Defragmentation is safe, with the risk of data loss being very small. Nevertheless, you must get into the habit of creating backups of your critical data before any disk operations to avoid unforeseen errors or power breakdowns.

3. Why should I defrag my SSD/HDD?

Unlike SSDs, defining helps to improve the performance of HDDs the most. SSDs, on the other hand, owing to their different technology, don't exhibit the same performance improvements as traditional HDDs due to a defragmentation process. Over-fragmentation is one of the factors that can reduce SSDs' durability.

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About the Author

Updated by Roxanne

Roxanne is one of the main contributors to EaseUS and has created over 200 posts that help users solve multiple issues and failures on digital devices like PCs, Mobile phones, tablets, and Macs. She loves to share ideas with people of the same interests.

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Product Reviews

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  • I love that the changes you make with EaseUS Partition Master Free aren't immediately applied to the disks. It makes it way easier to play out what will happen after you've made all the changes. I also think the overall look and feel of EaseUS Partition Master Free makes whatever you're doing with your computer's partitions easy.

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  • Partition Master Free can Resize, Move, Merge, Migrate, and Copy disks or partitions; convert to local, change label, defragment, check and explore partition; and much more. A premium upgrade adds free tech support and the ability to resize dynamic volumes.

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  • It won't hot image your drives or align them, but since it's coupled with a partition manager, it allows you do perform many tasks at once, instead of just cloning drives. You can move partitions around, resize them, defragment, and more, along with the other tools you'd expect from a cloning tool.

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