[3 Ways] Recovering Unallocated Space of A USB Flash Drive

What is unallocated space on a USB flash drive?

Are you experiencing the situation where your USB flash drive stops working and shows unallocated in Disk Management? If this happens to anyone, how frustrating the situation would be. Many users have met this issue when using a hard disk, USB drive, SD card, or pen drive. Any inappropriate action may result in unallocated space on the USB flash drive.  

"Unallocated" means this portion of the storage device has not yet been formatted and partitioned. It is ready for storing data. You couldn't access the unallocated space. If you want to use the unallocated space on a USB flash drive, you can create a new partition to occupy the space or allocate it to an existing partition.

Why does my USB have unallocated space?

It's important to know how unallocated space on a USB flash drive is created. Several reasons cause this issue. Unallocated space frequently occurs when users try to burn the system to a USB drive. Some operating systems, like Chrome OS and Linux, may change the partition system of a USB flash drive.  

Except for the system reason, accidental deletion and virus attacks are the most common reasons. Users may delete the partitions on the USB flash drive by mistake in Disk Management or with a partition manager tool. Malicious virus attacks could damage the partitions of USB flash drives.

Incorrect use of third-party software or incorrect formatting can also result in unallocated space on the USB drive or SD card.

How to recover unallocated space on a USB flash drive?

There are three efficient ways to recover unallocated space on a USB flash drive. If the whole USB flash drive becomes unallocated, you could recover files on the USB flash drive first and then create a new partition directly.

If one of the partitions on a USB flash drive becomes unallocated, professional partition recovery software could restore the partitions.

Method 1. Create a new partition directly

If the USB is brand new or you don’t need to recover data from the USB flash drive, you can directly create a new partition to use the allocated space.

Step 1. Connect the USB flash drive to the computer.

Step 2. Press Win + R and input “diskmgmt.msc” to open Disk Management.

Step 3. Right-click the unallocated space and select “New Simple Volume”.

Step 4. Follow the new simple volume wizard to create a new partition.

Method 2. Restore partitions from the unallocated USB drive

If you accidentally deleted a partition on the USB flash drive, you could use a reliable partition recovery tool to recover both the files and partitions on the USB. AOMEI Partition Recovery Wizard would be a great choice for you.

As one of the functions of AOMEI Partition Assistant Professional, AOMEI Partition Recovery Wizard allows users to recover deleted or lost partitions in HDD, SSD, USB drives, SD cards, and other storage devices. It supports NTFS partition recovery, FAT32, and Ext3/Ext4. AOMEI Partition Assistant is compatible with Windows 11/10/8/7/Vista/XP/Server.

To recover deleted or lost partitions on a USB drive, you could download and install AOMEI Partition Assistant Professional demo for a trial.

Step 1. Click “Partition Recovery Wizard” on the left panel of the main interface. Select the USB flash drive and click “Next”.

Step 2. Select a search mode. It’s recommended to choose “Fast Search” the first time.

Step 3. The program lists all the lost or deleted partitions on the USB drive. Select the partition you want to recover and click “Proceed”.

Step 4. Partition recovery will complete in seconds. You could go to Disk Management to check the USB drive partitions.

Method 3. Resize unallocated USB drive partition

To use the unallocated space on a USB flash drive, you could use AOMEI Partition Assistant to format the USB drive and then resize the partition to allocate the space to the existing partition. Because the data stored in the USB flash drive before will be erased, you could back up your data to other storage devices first and then follow the steps below to resize unallocated USB drive partitions.

Step 1. Launch AOMEI Partition Assistant and right-click the USB flash drive. Select “Format Partition”.

Step 2. Right-click the existing partition and select “Resize Partition”.

Step 3. Drag the slider to the end of the USB flash drive. The unallocated space would be added to the existing partition.

Step 4. Click “Apply” to confirm the operation. Within a few seconds, AOMEI Partition Assistant will recover the unallocated space of a USB flash drive.

Conclusion

There are three effective methods for recovering unallocated space of a USB flash drive. You could choose the desired way according to the USB drive state in Disk Management. It’s recommended to use AOMEI Partition Assistant to recover lost or deleted partitions on a USB drive or resize the USB flash drive partitions.

If there is unallocated space on a USB flash drive not due to partition loss, the data will face the risk of loss forever. Therefore, making a regular backup could be the best way to avoid data loss. It’s recommended to use the Windows backup freeware-AOMEI Backupper to create copies of vital data and partitions.