By Stephanie / Last update March 14, 2022

How do I get unallocated space back on Windows 10?




I partitioned my existing 500g drive and tried to copy the C drive to it and go with that. I used a tool to clone the drive and it deleted the partition. The partition becomes an unallocated space. How do I get unallocated space back on Windows 10? Is there any way to recover the lost files?




Have you ever run into the situation that a hard drive, external hard drive, or USB drive suddenly becomes unallocated? What should you do if the data on the unallocated partition is critical?

Partitions are several hard drive parts that have been logically separated to store the data. One hard drive could have multiple partitions. When you see unallocated space on the hard drive, it means that this hard drive space hasn't yet been allocated to a partition.

The best ways are provided in this post to help you get unallocated space back on Windows 10 and recover unallocated partitions with data on it.

Reasons for unallocated partitions in Windows 10/11

Before learning about the methods to recover unallocated partitions in Windows, knowing the reasons for unallocated disk space is important to avoid the same scenario in the future. There are many factors that could result in unallocated partitions. Check the common reasons for unallocated partition on your hard drive.

Accidental partition loss or deletion. If a partition is deleted, lost, or corrupted due to kinds of reasons, the space of the partition will become unallocated in Disk Management.
 Unexpected power error. If your computer has some unexpected power issues when writing data to the hard drive, some data will be corrupted and partitions become unallocated space.
 Hardware failure. If there are some problems with the hard drive, the partitions could be lost and become unallocated.
 Virus attack. Some viruses can target the partitions of your hard drive. The partitions could be deleted.
 File System errors.

Tips: If the partition becomes unallocated, you need to stop adding new data to it. At the same time, use a professional partition recovery tool to perform partition and data recovery right away. Otherwise, the data on the unallocated partitions will be overwritten, and couldn’t be recovered anymore.

How to recover unallocated disk space with data on it?

To recover unallocated partitions in Windows 11/10/8/7, AOMEI Partition Assistant Professional is the best choice. Professional partition recovery software could solve the problem directly and easily if you don’t have any backup files.

AOMEI Partition Assistant is a powerful partition manager to help users perform kinds of disk partitioning without any technical knowledge. Partition Recovery Wizard is a built-in feature of AOMEI Partition Assistant. It allows you to recover unallocated partitions and data with three simple steps if the data hasn’t been overwritten.

Main features of AOMEI Partition Assistant Professional
AOMEI Partition Assistant Professional provides a wide range of functions on a user-friendly interface, making PC disk partition management easier and safer than ever before.
 Comprehensive Partition Manager: It allows you to resize, move, merge, split, format, create, align, and delete partitions.
 Converter & Wizard: AOMEI Partition Assistant has some advanced functions like MBR/GPT disk converter, dynamic/Basic disk converter, NTFS/FAT32 converter, make bootable CD wizard, disk & partition clone wizard, etc.

You could download AOMEI Partition Assistant Professional Demo to recover unallocated partitions in Windows computers.

Download Demo Win 11/10/8.1/8/7/XP
Secure Download

Step 1. Select “Partition Recovery Wizard” on the left panel of the main interface. Choose the disk that includes unallocated partitions.


Step 2. Select a scanning method. Fast Scan & Full Scan. It’s recommended to choose Fast Scan for the first time because it saves a lot of time. Click “Next”.


Step 3. Choose the searched partitions. All the lost or deleted partitions will be listed and you could select the partition you want. And then click “Proceed”.


The unallocated partitions will be recovered after you see the “Congratulations” page. You could go to Windows File Explorer to check the partitions and data.

How to fix unallocated partitions using CMD?

With AOMEI Partition Assistant Professional mentioned in the previous section, fixing an unallocated partition in Windows 10 is simple. You can also try to fix unallocated space on your hard drive and recover lost partitions via CMD.

CMD can help you repair a hard drive that has recently lost a partition. It may be necessary to manually delete the partition. You can delete the existing partition and create a new one with the diskpart command. But the data on the unallocated partition will be erased.

Step 1. Type “CMD” in the search bar and select “Run as administrator”.

Step 2. Input the following command and press Enter after each one.


list volume

select volume (number)

delete volume

delete volume override


After deleting the unallocated partition, you could go to Disk Management to create a new simple volume. Right-click the Start menu and select Disk Management. And then right-click the unallocated partition. Select “New Simple Volume”. Follow the New Simple Volume Wizard to create a new partition without any data.


Wrap it up

If the partitions get unallocated space, it is the best way to recover unallocated partitions and data on it with AOMEI Partition Recovery Wizard. It makes recovering lost partitions and data from unallocated space a breeze.

If you have more operations on unallocated partitions or only want to recover specific files from the unallocated disk space, professional data recovery software-AOMEI Data Recovery for Windows is of great help.

Of course, the most important to avoid partitions and data loss is to make regular backups. Windows backup freeware-AOMEI Backupper is a rare excellent tool to back up, restore and clone your disks and partitions.