How to Fix the USB Drive Unallocated Issue? [4 Methods]

On this page, we list 4 different ways to fix the USB drive unallocated issue. Besides, we will tell you how to recover data from an unallocated USB drive without losing data.


By Zoey / Updated on April 2, 2024

Share this: instagram reddit

If you find your USB drive's available storage space inexplicably reduced, the culprit might be USB drive unallocated space. To verify this, delve into your PC's Disk Management console. If, indeed, unallocated space exists, it can be transformed into usable storage using the appropriate tools at your disposal.

Unallocated Space in Disk Management

Important Note: Before attempting to rectify the issue, ensure you recover any data from the unallocated space to fix unallocated external hard drive without losing data.

Unallocated Space on USB Drives

Encounters with USB unallocated space often happen when you're installing Windows or accessing the Disk Management console. In the realm of USB drives, unallocated space may emerge following the installation of operating systems like Chrome OS or Linux-based OS options.

Unallocated space signifies portions of your USB flash drive that lack partitioning. Such space eludes Windows' accessibility, rendering it impossible to read from or write to.

Converting this unallocated territory into allocated space is feasible, but prior to doing so, ensure data retrieval from this space to prevent data overwrite. Let's delve into strategies for recovering unallocated space of a USB drive that might seem out of reach, followed by methods for fixing the unallocated space.

How to Fix USB UnallocatedIssue

Our focus shifts to allocating unallocated space within USB drives. Four distinct methods are available for unallocated USB drive fixing, each method elucidated in a comprehensive step-by-step manner.

Method 1. Create a New Partition

The Disk Management console is your gateway to orchestrating storage devices within your Windows environment. This tool facilitates the creation of fresh partitions from unallocated space within your storage device.

1. Initiate the Disk Management console by pressing Win + R, entering disk mgmt.msc, and pressing Enter.

2. Identify the unallocated volume, right-click it (labeled as such), and opt for New Simple Volume.

Click New Simple Volume

3. An installation wizard for generating a new volume will appear. Proceed with Next.

New Simple Volume Click Next

4. Subsequently, stipulate a size for the new partition and proceed with Next.

Specify Volume Size Next

5. Opt for a desired drive letter for the new partition, followed by another Next.

Assign Drive Letter or Path Click Next

6. Choose a File system and provide a Volume label before proceeding with Next.

Format This Volume Next

7. Conclude by selecting Finish, thereby creating a new partition.

At this time, the previously unallocated space should show as a volume accompanied by the assigned drive letter.

Method 2. Use DiskPart

DiskPart, a command-line utility, proves invaluable for transforming unallocated space on a USB drive into a functional partition.

1. Begin by launching Command Prompt with administrative privileges via Win + R, "cmd," and Ctrl + Shift + Enter.

2. Execute the following commands:


list volume

CMD Diskpart

3. A listing of available volumes will materialize. Locate the volume housing unallocated space and employ the subsequent command:

select volume X

(Substitute 'X' with the pertinent disk number)

Diskpart Select Volume

4. Execute the subsequent command:

create partition primary

5. Conclude by formatting the disk into the desired filesystem. For NTFS formatting, execute these commands:

format fs=ntfs quick


At this stage, access to the unallocated space should be reinstated.

Method 3. Update or Reinstall USB Drivers

Obsolete or malfunctioning device drivers can culminate in USB unallocated space. These drivers are instrumental in facilitating communication between storage devices and the broader hardware framework. Issues arise when these drivers underperform.

Step 1. Establish a connection between the external hard drive and your Windows PC. Subsequently, press "Win + X" and select "Device Manager."

Device Manager

Step 2. Identify "Disk Drives" and expand this category.

Step 3. Opt for "Update driver" or "Uninstall device" based on your preference after right-clicking the intended external hard drive.

Update Driver

Step 4. Following a Windows PC restart, the operating system will automatically reinstall the hard drive. Alternatively, select "Browse my computers for drivers" to locate and install the latest driver.

Browse My Computer fro Drivers

Ensure to save changes by clicking "OK."

Method 4. Expand Volumes

Additionally, merging available space into another partition is plausible with the following steps.

Step 1. Connect your external hard drive to your PC, then employ "Win + X" and select "Disk Management" to activate the Windows utility.

Step 2. Right-click your external HDD and choose "Extend Volume."

Extend Volume

Step 3. Specify the desired disk and space extension, then proceed with Next and Finish.

Select Disk Click Next

Efficient Recovery of Data from Unallocated USB Drives

In the realm of data retrieval from unallocated USB drives, few approaches match the efficiency and safety of professional data recovery software. It's paramount to adopt the best data recovery software for unallocated partition.

Deeply rooted in the field of data recovery, MyRecover extends its capabilities to retrieve deleted and missing files from both unallocated and healthy USB drives.

  • After data loss, it's advised to refrain from writing new data to the USB drive.
  • After the USB drive data recovery, store the recovered data in a new location.
  • MyRecover provides a no-cost allowance of 500MB file recovery. For substantial file recovery from your external hard drive, consider upgrading to MyRecover's Professional or Technician edition.

Key Features:

📌 Recovery of diverse data types from internal and external hard drives, USB drives, SSDs, and more.

📌  Search Simplicity: Quick Scan and Deep Scan ensure comprehensive file retrieval. Locate files swiftly via Filename, Path, Date, Size, and more.

📌  User-Friendly: Recovered files maintain their original Paths, Filenames, and Formats.

📌  Broad Compatibility: Support for NTFS, FAT32, exFAT, and ReFS file systems, alongside compatibility with Windows 11, 10, 8, 7, and Windows Server.

Step 1. Attach your USB drive to your Windows PC. Launch MyRecover. Hover the mouse over the drive saved deleted files before, and click Scan.

External Hard Drive Start Scan

Step 2. Employ filtering options such as Name, Date, Document Type, or Path.

Name: Input specific filenames to narrow down search results.

Date modified: Define the date range for search results (today, yesterday, last 7/30 days, etc.).

Size: Filter by file size (<128KB, 128KB1MB, 1MB512MB, etc.).

External Hard Drive Scanning

Step 3. Navigate to the Other Missing Files folder and select the desired data. Conclude by clicking "Recover x files" to initiate USB drive data recovery.

External Hard Drive Recover Files

Final Thoughts

Encountering USB drive unallocated space can evoke discomfort and anxiety. Nevertheless, effective resolution is attainable with appropriate recovery tools. Opting for a proficient solution like MyRecover enhances data recovery prospects significantly. Key steps include immediately stopping the USB usage, launching MyRecover for data recovery, and subsequent USB drive rectification.

Zoey · Editor
Zoey works as an English editor of AOMEI Technology. She provides tech information about backup and restore, mobile data transfer, and so on for AOMEI. She hopes that her articles will be greatly helpful for users. She is fond of music, film, and photography.