By Lora / Last update May 6, 2022

Partitions are some logical parts divided and allocated by the partition editor on the disk. Different files and data are stored in these allocated partitions. Users can manage different data and files through the partition.

But if due to certain reasons, your partition was marked with “Unallocated”, which means that this part of space is not allocated to any volume, and no data can be written in this unallocated space.


Where does unallocated partition come from?

Then you may wonder where these unallocated partitions come from and how they are generated. You may ask yourself, “Did I do something wrong? Was it because I Had deleted that partition that it went unallocated?”

It can be said affirmatively that the deletion operation will cause unallocated volume. But to be honest, a good deal of reasons can lead to unallocated partition. Check them as follows.

Deletion operation. If an accidentally deleted partition occurs, it won’t be shown in the Windows File Explorer; what’s more, in Disk Management, it will be marked as “Unallocated”.

Unexpected shutdown. An unexpected shutdown is not only likely to cause your device to malfunction, but if there is a power outage while your device is being repartitioned or resized, it is likely to cause partition loss, thus cause volume.

Partition Table corruption. Partition Table records the starting and ending positions, sizes, and other information of the partitions. Once the partition table error occurs, the partitions are very likely to be lost, which will cause the partitions to become unallocated.

Virus Infection. Viruses and malware will cause damage to your file system, partition table, or some else important features and tools of your device, leading to partition loss and unallocated partition.

Damaged storage device. Take a USB flash drive as an example, if you unplug the USB flash drive while it is writing data, it may cause physical damage or damage to the file system, leading to unallocated volume.

How to perform unallocated partition recovery?

Now you may know why there is an unallocated partition on your device. Different situations have respective solutions.

It is worth mentioning that if you encounter an unallocated partition caused by a virus, firstly, please use anti-virus software to check and kill the virus regularly, then turn to unallocated partition recovery software for help, which will be introduced right away;

If your hard disk has suffered physical damage, please contact the data recovery service as soon as possible and seek help from professional technicians;

If you accidentally delete your partition or regret the deletion, you might as well choose a trusty tool--AOMEI Partition Recovery software. As a professional software, it facilitates users to manage partitions with ease.

Case 1 Recover unallocated partition with AOMEI Partition Assistant

Tips: After deleting the partition, do not use the hard disk for reading and writing operations, so as not to overwrite the data still stored in the unallocated space, which may never recover the data.

Step 1. Install and launch AOMEI Partition Assistant on your PC. You can use it for a free trial.

Download Demo Win 11/10/8.1/8/7/XP
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Step 2. Get to Wizards on the left side of the window and click Partition Recovery Wizard. Select your deleted partition that needs to be recovered, then click Next to go to the next step.


Step 3. Two search modes are prepared for you to adopt. Generally speaking, it’s highly recommended you try Fast Search first to save your time, if that does not work efficiently, try Full Search. Then click Next to start scanning.


Step 4. Then all the lost partitions will be shown in the list box, select the one you want to recover, then click Proceed.


When finished, a notice of congratulation will pop up, and the lost partition will come back successfully. You could also use this tool to recover accidentally deleted partition.

Case 2 Deal with unallocated space

If the method above does not fit your situation and budget, you can also try the methods below to deal with the unallocated volume.

To make use of unallocated partition, users can use the embedded trusty tool Disk Management, or also, try a much easier and safer way, taking advantage of AOMEI Partition Assistant.

Here are two kinds of choices you can adopt. On one hand, you can use this part of space to create a new partition if the space of your other partitions is enough for storage.

Method 1. Create a new partition

When using Disk Management to create a new volume, Perform a quick format enables you to create a new file table without completely erasing the contents of your hard drive, and we recommend ticking this option.
Windows allows users to create a certain limit on the size of the partition, the minimum is 8 MB, and the maximum depends on the size of the unallocated volume on your hard disk. You can allocate it according to your preferences and needs.
Use Disk Management

Step 1. Right-click the Start button, then click Disk Management in the list.

Step 2. Locate the unallocated partition and right-click on it, select New Simple Volume.


Step 3. Then you will receive a welcome notice of New Simple Volume Wizard, click Next.


Step 4. Fill in the Simple Volume Size you prefer, then click Next to continue.


Step 5. Assign a drive letter and path to this new partition. Click Next to go on.


Step 6. To store data on the new partition, you need to format it first. Give a name to the new partition on the Volume label, Tick Perform a quick format.


Then a new volume will be successfully created.

Use AOMEI Partition Assistant

Compared with the method utilizing Disk |Management above, making use of AOMEI Partition Assistant is a much more convenient way to carry out unallocated partition recovery.

Step 1. Install and launch AOMEI Partition Assistant on your PC to use it for a free trial.

Step 2. Locate your deleted partition and right-click on it, select Create Partition in the list.


Step 3. You can decide the size of the new partition by dragging the knob left or right. Assigning the drive letter is practicable as well.


Step 4. Then click Apply on the upper-left corner of this window to confirm your operation.


By utilizing this professional program, a new partition will be created safely and efficiently.

Method 2. Merge unallocated space into another partition

If you feel that other existing partitions have insufficient storage space and want to expand their capacity, you can also choose to add the unallocated space into other partitions.

Use Disk Management
The system retention partition and partitions on different hard drives cannot be merged.
You can only apply this feature when the unallocated partition is adjacent to the target partition.

If the Extend Volume greyed out, maybe you should launch this tool via Computer Management and choose Run as administrator. Then go to Disk Management.

Step 1. Start Disk Management with the shortcut Win+R and input diskmgmt.msc.


Step 2. Choose the partition you want to extend, right-click on it and select Extend Volume.


Step 3. A welcome notice of Extend Volume Wizard will show up, click Next.


Step 4. Select disks and specify the space you want to extend. Then click next > finish.


Then the unallocated volume will be successfully merged into another partition.

Use AOMEI Partition Assistant

Instead of using the labor-consuming Extend Volume Wizard tool, users might as well try another more efficient way.

Step 1. Install and start AOMEI Partition Assistant to use the demo version for a free trial.

Step 2. Locate the target partition you want to extend its volume and right-click on it, select Merge Partitions.


Step 3. Select the unallocated partition and click OK.


Step 4. Click Apply on the upper-left corner to confirm.


Then the target partition will be extended easily and safely.


To perform unallocated partition recovery, hope the Demo version of AOMEI Partition Assistant helps you out. To carry out some of the advanced operations you can upgrade it to the AOMEI Partition Assistant Pro version.

The Pro version can also facilitate you dynamically managing disk, like resizing, moving, creating, or formatting, moreover, enables you to extend a partition to enlarge the NTFS system without a reboot.

What's more, a good Windows data rescue application - AOMEI Data Recovery for Windows can help you out if you need to restore deleted or lost data from hard disks.