How To Fix & Recover Unallocated Space On USB Drive [2023 Updated]

Have you ever come across a situation where your USB drive or any other external drive shows you unallocated space on your PC?

Now if this happens to anybody then I can understand how frustrating the situation would be to fix and recover unallocated space on the drive. Actually, unallocated space can be seen on a USB drive or SD card is because of the loss of partition.

This creates a havoc situation and users think that a drive is damaged forever and cannot be repaired anymore. But this is not true, one can easily fix the unallocated space on USB drive or any other data storage media by applying the solutions mentioned here.

Apart from that, here I will also be going to discuss how to recover unallocated space on USB drive using USB Drive Data Recovery Tool.

  • What Is Unallocated Space On USB Drive?
  • Why USB Drive Lose Space?
  • Can Unallocated USB Drive Data Be Recovered?
  • How To Recover Unallocated Space On USB Flash Drive Using USB Drive Recovery Tool?
  • Recovering Unallocated Space Of A USB Flash Drive Without Software
  • How To Fix Unallocated Partition On USB Drive?

Before proceeding further to recover unallocated space external hard drive, let’s take a look at one of the real user’s examples.

Practical Scenario:

What Is Unallocated Space On USB Drive?

Just imagine you have a USB drive of 16GB and you want to know how much space does it have. When you see the space on it then it is not showing the exact space that should be available. It means that low space is showing and you are much worried because you have some important files on it.

Now, this is called an unallocated disk space and you cannot use this space unless disk space is allocated. The space that is taken in the USB drive is the program files, some other files, or some fragments generated by OS.

Why USB Drive Lose Space?

To see how much space is left on USB drive or SD card, you plug it into your PC but you were surprised to see that only a few MB was left.

To know further, why it happens, simply open Disk Management (Windows built-in utility) just to check what actually happens. There you can see that lost space is marked as unallocated. It completely means that the unallocated space that you see on a USB drive or SD card is because of the loss of partition.

How this happened is important to know? Well, it’s already mentioned that the lost space often occurs when users try to burn the system to USB drive. For example, Chrome and Linux have the ability to change the partition system of the removable disk, and hence, space will become low on either SD card or USB flash drive.

In addition, the cause behind the error, another one includes is the installation of third-party software inaccurately. Many times, formatting the drive does not process successfully which in return shows you as unallocated space.

Now the question arises- how to recover unallocated space on USB flash drive or can unallocated USB drive data be recovered?

Don’t worry, read further to get the answer to these questions…

Can Unallocated USB Drive Data Be Recovered?

The answer to this question is Yes, unallocated USB drive data can be easily recovered.

Now, you must be thinking, how? Let’s find out the answer…

Well, you can recover data from unallocated USB flash drive by using the most recommended USB Drive Data Recovery Tool. Once you have restored the data with help of this software, now you can create a new partition or extend the existing partition.

How To Recover Unallocated Space On USB Flash Drive/SD Card Using USB Drive Recovery Tool?

Though the situation might frustrate you as you don’t know how to solve such condition but don’t worry, there are ways that can easily solve the less space error showing on your USB drive. Bur before fixing the unallocated partition issue, it is essential to recover unallocated partition free.

When you lose all your data due to some unexpected reasons, then using a recovery program will be the best way to restore all erased data from USB drive.

With the use of the USB Drive Recovery Tool, you can restore all lost/inaccessible files from USB drive. This tool is designed to rescue all types of data such as photos, audio, and videos.

No matter whatever reasons the files were deleted from USB flash drive, it will deeply scans your drive and find the lost files and restores them with ease.

* Free version of the program only scans and previews recoverable objects.

Watch This Video Tutorial On How To Recover Files From USB Flash Drive

Step 1: Select Desired Location

Firstly, select the drive, external media or volume from which you want to recover deleted media files. After selecting, click on ‘Scan‘.

Step 2: Preview Recovered Media Files

Next, you can preview the recoverable media files after the scanning process is completed.

Step 3: Recover Media Files

Lastly, you can select the images, audio, video files you want to restore and click on ‘Recover‘ option to save them at the location you want.

Recovering Unallocated Space Of A USB Flash Drive Without Software

A backup is a primary option for each and every user to keep their day-to-day data safe. Thus, if you have made a backup of the USB flash drive data then recovering unallocated space of a USB flash drive files can be easily done through the backup option.

That’s why restoring from the backups is perhaps the most efficient way of bringing back all stuff that was deleted.

How To Fix/Recover Unallocated Partition On USB Drive?

Apart from the above solution, you can also try the below two more alternative ways to recover unallocated space on USB drive and they are as follows:

Sol 1: Using Disk Management

Sol 2: Using Command prompt (DiskPart command)

Watch this Video Tutorial to Learn How to Recover Unallocated Space On USB Drive

Solution #1: Recover Unallocated Space On USB Drive Using Disk Management

You have already read about Disk Management that is Windows built-in utility and opening this will show you space as unallocated on USB drive. Follow the steps to recover low space on USB drive/SD card.

Step 1: First, connect your USB drive to PC and then open Disk Management

For Windows 8/10, to open Power User Task menu, press Win + X and then tap on Disk Management

For Windows 7, tap Start option to open Start Menu and after, that type Disk Management and press Create and format

NOTE– Before you proceed with this step, kindly backup all data in the USB drive. After that, press on YES option when popup occurs. Doing this will create a USB drive as one portion of low space.

Step 3: Now when the complete USB drive becomes unallocated space, simply right click and choose New Volume option


Step 4: After that, you will get a popup of Partition Wizard where you have to choose Primar Drive as partition type. Now select partition size and allocate a drive letter to USB drive.

Step 5: At last, tap on Finish option when the process is over and you can easily access the drive.

Solution#2: Restore USB Flash Drive Unallocated Space Using Command Prompt

You can even use the DiskPart tool to bring your lost/unallocated USB space. Here are the easy steps for how to recover unallocated partition using CMD DiskPart tool:

  • First, connect an USB drive to your PC.
  • Now, open Run dialogue box and type diskpart > enter

  • Here you have to type list disk on Diskpart window after which all disks with number will be seen on the system. You will see two-disk space: Hard disk drive as 0 and USB flash drive as Disk 1
  • Now type Select Disk 1 and press Enter. You will see ‘Disk 1 is now the selected one
  • Clean all volumes and partitions by typing Clean command on USB drive
  • After that, you have to create primary partition by typing create partition primary command
  • When it is done, type Exit to close window

Using Diskpart method is considered as the best way to recover unallocated space on USB flash drive or SD/memory card. Its time to format the drive so that the low space can be accessible for using it.

But at the same time, you should also be careful in moving further because there is a chance to lose all your data from USB drive. In such situation, what can be done to get back those data from USB drive?

Frequently Asked Questions:

Bottom Line

At some point of time, it is quite possible to lose unallocated space of USB flash drive. In that case, you can easily recover unallocated space of USB flash drive using the best USB drive data recovery methods.

In this blog, the complete recovery solution will help you to know the best ways of recovering unallocated space of a USB flash drive.

So, without wasting any time, just try these ways and get your problem solved.

— Update: 19-03-2023 — found an additional article How to Repair and Restore Unallocated Space on a USB/SD Card from the website for the keyword fix unallocated space error on usb drive or sd card.

Applies To: USB, SD Card, Pen Drive, and Other Removable Storage Devices

Problem: USB/SD Card Stops Working, Showing As Unallocated

Have you ever met this problem that your SD card or USB drive suddenly shows as unallocated or even stops working on your PC? Afterward, you can neither access data nor save new data on it. Many users have encountered the issue that a used storage device, like a hard disk, USB, SD card, or pen drive, is missing under File Explorer and is marked as “Unallocated” in Disk Management, which is quite confusing and annoying.

What Is Unallocated Space on a USB/SD Card

“Unallocated” is a state indicating that this part of space on the storage device hasn’t been formatted and partitioned yet and thus is not ready for data storage. You can neither access the unallocated space under the computer drives or write data to it. To utilize unallocated space, you can either create a new partition using the space or add it to an existing partition.

When Will You See Unallocated Space

As mentioned, the space that is not assigned to a partition by Windows is called “unallocated space”. Therefore, the space on a newly initialized disk or the space that is left free will all show as “Unallocated”. An existing partition on a hard drive, external hard drive, USB, SD card or other removable disks may also become unallocated space after some operations.

Why Does a USB/SD Card Become Unallocated Suddenly

The commonest reasons are deletion and virus attack. For example, you may accidentally delete the partition on the USB or some program does this for you. It’s also possible that you were doing some operations that required you to delete partitions but you didn’t realize it. Besides, it’s not surprising that malicious virus attacks may bring various negative results, including a USB becoming unallocated.

In such cases, data loss always coincides with the partition’s change to unallocated space. Fortunately, you can repair an unallocated USB or SD card and retrieve your files with ease.

How to Fix and Repair an Unallocated USB/SD Card

Depending on whether you need to perform data recovery, there will be different solutions for you.

Method 1. Create a New Partition Directly

If the USB is brand new or you have no intention to perform data recovery, you can create a new partition using the allocated space directly to make the space usable.

To create a partition using unallocated space on a USB/SD card:

Step 1. Connect or insert the USB/SD card to the computer.

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

Step 4. Follow the wizard to finish the remaining process.

Method 2. Restore the Partition from the Unallocated USB

However, if you attempt to repair a used USB or SD card that contains precious files and becomes unallocated unexpectedly, you should perform data recovery.

To recover both the files and the partition on the USB all at once, perform a partition recovery using the partition tool – EaseUS Partition Master is a workable choice for you. EaseUS Partition Master will restore both the data and the partition for you from the unallocated space on the USB or SD card. Thus, it spares you the steps to create a volume manually. (Or you may want to recover data from the unallocated space only and then create a volume as you like.)

To repair the unallocated space on the USB/SD card:

Step 1. Connect the external storage device to your computer for lost partition recovery. To begin with, click “Partition Recovery” on let menu. Then choose the target disk and click “New Scan“.

Step 2. EaseUS Partition Master will run “Quick Scan” and “Full Scan” modes to find and display all the existing and lost partitions the selected disk.

Double-click on a partition will allow you to preview the content.

Step 3. Select the partition marked with a “Lost” Status and click “Recover “.

Step 4. Wait and click “Done“when the software applishes the final recovery .

Step 5. Go to the Partition Manager section, your lost partition on your device should reappear in the drive.

Knowledge Base: Unallocated Space VS Free Space

Both the unallocated space and free space you see in Disk Management are unusable spaces. When you shrink a logical partition, you will get free space, while a primary partition the unallocated space. Based on the information, you can easily conclude that they are identical and both unallocated space and free space are actually “unallocated” space. 

In addition, free space may also refer to the unused space in an existing partition, disk, or external storage device. It’s usable compared with the chunk marked as free space in Disk Management.

The Bottom Line

Conclusively, you can fix an unallocated USB/SD card/pen drive by establishing a new volume. One thing you need to consider is whether you need to recover data from the unallocated space. If you do, use software like EaseUS Partition Master to restore your partition (including data) or use EaseUS Data Recovery Wizard to recover only data from the unallocated removable disk.


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