How to Perform Unallocated Hard Drive Data Recovery?

How to perform unallocated hard drive data recovery? Get efficient ways to solve this issue in this article. You can also fix unallocated external hard drives and get useful data loss prevention tips.


By Penny / Updated on April 2, 2024

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Is it possible to perform unallocated hard drive data recovery?


I have a 1.5 TB Seagate Barracuda drive that I’ve used as a backup drive and for extra storage. Recently, it stopped showing up on My Computer (it worked fine one day, but the next day nothing). Moreover, in Disk Management, it shows up as unallocated with all right-click options greyed out. Unfortunately, I don’t have any backups. So how can I recover data from unallocated drives? Thanks in advance.

-A user from Toms Hardware

Many users ask questions about what is unallocated space. In general, unallocated space is the space where Windows cannot read or write data. To access unallocated space, you need to ask for help from the Disk Management utility because you cannot access it via Windows File Explorer.


Unlike free space, unallocated space needs you to allocate it by creating a new partition or expanding an existing one. After that, you can recover unallocated partition with data it.

Why a partition becomes an unallocated space?

If you’re on this page, which suggests this space is essential to you because unallocated space often contains a large number of deleted files. Let’s have a closer look at possible causes for unallocated space.  

Deleted or lost partition: If you accidentally deleted partitions or intentionally deleted partitions, this partition might become an unallocated space.
Hardware failure: Hard drives are prone to failure. Once collapsed, the partition could be lost.
Unexpected power failure: If your desktop or laptop loses power while writing to your drive, some data may be corrupted, and the related partition may be destroyed.
Virus attacks: If a virus automatically deletes your partition, this erased partition might appear as unallocated space. And viruses also make Windows automatically delete files.
Poor connection: Poor connection could discourage your PC from sufficient power.  

Part 1. How to recover unallocated partition with data on it?

Are you seeking ways to recover unallocated partition with data on it? Please check the following two phases.

In brief, you need to recover deleted & missing partitions first. If the deleted files on your retrieved partition have been overwritten, please read further to recover deleted & lost files from hard drives. 

Phase 1.  Recover deleted & lost partitions via AOMEI Partition Assistant

As stated earlier, deleted or lost partitions is among the possible reasons for unallocated space. Those users who’ve deleted partitions might be eager to recover deleted & lost partitions with data on them.

If it happens to be your case, the highly-praised AOMEI Partition Assistant Standard is right for you because it enables non-tech users to recover deleted & lost partitions with easy steps. As long as there’s no overwritten data, this tool makes it possible to recover unallocated partition with data on it.   

Other highlights of AOMEI Partition Assistant:
Deal with fixing errors using CHKDSK.exe, disk formatting, merge partitions, partition creation, partition resize, etc.
Perform disk conversion between MBR and GPT, OS migration, etc.   
Support Windows 11, 10, 8.1, 8, 7, Vista, and XP (32/64-bit) computers.
Download Demo Win 11/10/8.1/8/7/XP
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Step 1. After running this software, click “Partition Recovery Wizard” on the left panel and select your external hard drive. Then click the “Next” button.


Step 2. To find your deleted or lost partitions quickly, please choose “Fast Search” and click “Next” to go on.


Step 3. After scanning, you can see all the recoverable drives. Please select your desired external HDD and click the “Proceed” button.


After the partition recovery process, you’ll receive a Congratulations message. Please click “Finish” to exit this window.

Phase 2. Recover deleted files from hard drives via data recovery software

Any changes to the unallocated partition could lead to further damage and decrease the data recovery rate. Thus, you’d better perform unallocated hard drive data recovery via MyRecover first, then fix your unallocated hard drives.

Supported by AOMEI Tech, this highly-praised data recovery tool is good at recovering deleted and missing files from unallocated or healthy local hard drives. After data loss, please avoid writing new files on your Windows.

Highlights of MyRecover:
  • Powerful features: Recover deleted & lost Word, Excel, PPT, folders, compressed files, photos, songs, videos, audio, websites, and other 200+ different types of data from internal & external hard drives, USB, SSD, etc.
  • Easy-to-find: Quick Scan and Deep Scan can find your deleted & missing files as many as possible. You can also quickly locate your desired files by Filename, Path, Date, Size, etc.
  • Convenient: Get deleted files’ original Paths, Filenames, and Format after recovery.
  • Excellent compatibility: Support NTFS, FAT32, exFAT, and ReFS file systems and be compatible with Windows 11, 10, 8, 7, or Windows Server.
Download Software Windows 11/10/8/7/Server
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Step 1. After running MyRecover on your Windows. Hover the mouse over the unallocated drive saved deleted files before, and click Scan.


Step 2. Filter your needed data according to Name, Date, Document Type, or Path.

  • Name: Type the filenames of your desired files to narrow the search area.
  • Date modified: Set the date (today, yesterday, last 7/30 days, and so on) according to your situation.
  • Size: Filter the file size (<128KB, 128KB~1MB, 1MB~ 512MB, etc) based on your needs.


Step 3. Go to the Deleted Files/Recycle Bin/Other Missing Files folder and select your needed files. Then click “Recover x files” to begin the unallocated hard drive data recovery process.


After unallocated hard drive data recovery, please save retrieved data in a new path.
MyRecover enables you to recover 500MB of files for free. To easily recover a large number of deleted and missing files from your internal & external hard drives, please consider upgrading MyRecover to the Professional or Technician edition.   

Part 2. How to fix unallocated external hard drives?

Besides internal hard drives, external hard drives also often turn into unallocated space. Let’s take unallocated external hard drives as an example. Please refer to the fixes below.

Fix 1. Create a new simple volume via Disk Management

As mentioned above, creating a new partition is a feasible way to fix unallocated disks. In this scenario, Disk Management is a good helper for you to perform varied Windows advanced storage tasks including creating a new simple volume.

This Windows system utility also can recover hidden partitions in Windows 7, 8, 10, or 11 computers.

Step 1. After connecting your external hard drive to the Windows, press “Win + X” and select “Disk Management” to open it.


Step 2. After entering the interface of Disk Management, right-click on the unallocated space and click the “New Simple Volume” button.


Step 3. Click “Next” on the Welcome to the New Simple Volume Wizard window.


Step 4. On the Specify Volume Size window, enter a smaller simple size volume in MB and click the “Next” button.


Step 5. Assign a new drive letter for the new drive and click the “Next” button.


Step 6. To erase all the existing data on your external HDD and make it ready for further use, select Format this volume with the following settings > perform a quick format > Next. Please ensure your selected file system is NTFS.


You can also create new partitions with another professional partition manager software, AOMEI Partition Assistant Standard without paying.

Step 1. Run this tool on your Windows PC and right-click on your unallocated partition. Then select the “Create Partition” option.


Step 2. Decide the new partition size > assign a new drive letter > choose the file system. Then click the “OK” button.


Step 3. Click “Apply” to save these changes.


Fix 2. Extend volumes via Disk Management

After salvaging data from your unallocated disk, let’s perform how to fix unallocated external hard drives without losing data by merging the free space into another partition. Please note that you’re only allowed to add the space to a partition that is adjacent.

Step 1. After connecting your external hard drive to the PC, press “Win + X” and select “Disk Management” to open this Windows utility.


Step 2. Right-click on your external HDD and select the “Extend Volume” option.


Step 3. Choose the disk and specify the space you want to extend, then click Next > Finish.


At this point, AOMEI Partition Assistant Standard also can help you merge partitions.

Step 1. Right-click on the partition next to your unallocated hard drive and choose the “Merge Partitions” option.


Step 2. Locate your unallocated hard drive and click the “OK” button.


Step 3. Click the “Apply” button.


Bonus tips: How do I protect files on my hard drive?

No one wants to suffer data loss again. If you’re seeking ways to protect your hard drive, please consider the following data loss prevention measures and put them into action.

  • Keep your PC or other portable devices clean
  • Avoid high temperatures and humid environments such as liquid or milk
  • Please think twice before permanent deletion
  • Don’t empty your desktop Recycle Bin from time to time
  • Avoid interruption as your PC or external hard drive reads, writes, or transfers data
  • Gently eject your external hard drive and do not drag it
  • Cultivate a good habit of making regular file, partition, disk, or system backups  
  • Run the latest antivirus software to protect your PC

As you can see, prevention always remains a better course of action than cure. In other words, only regular backups can prevent data loss at the source.

If you’re reluctant to use different Windows backup features to back up files, or systems separately, why not give this AOMEI Backupper a chance?

This free backup software for Windows offers you a richer, more flexible, and better user experience. For example, you can back up files, folders, partitions, disks, or systems at the same time via this tool.

Download Freeware Win 11/10/8.1/8/7/XP
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Phase 1. Make a file backup via AOMEI Backupper

Step 1. After launching AOMEI Backupper on your Windows PC, select “File Backup” under the Backup tab.


Step 2. Click “Add Folder/Add File” to add the files/folders you want to back up.


Step 3. Locate a saved path to store your backup files/folders. Then click the “Start Backup” button.


Step 4. After the backup process, click “Finish” to exit the window.


Phase 2. Restore files from backups via AOMEI Backupper

Step 1. Under the Restore tab, click the “Select Task” button.


Step 2. Select your File Backup and click the “Next” button.


Step 3. Select the specific files/folders you want to restore. Then click the “Next” button.


Step 4. Select “Restore to original location” or “Restore to a new location” as you need. Then click “Start Restore” to begin the restoration process.


If you need to perform unallocated hard drive data recovery, please refer to the first two parts.

Penny · Editor
Penny works as an editor at AOMEI Technology, while she's a tester and editor for AOMEI Data Recovery Tools. She enjoys helping users with data recovery issues on Windows and iPhones using simple and practical solutions. Outside of work, she has a strong affection for pets, particularly giant pandas.