3 Methods to Fix Unallocated Space on USB

Theo Lucia

May 07, 2025 • Filed to: Recover Files • Proven solutions

SD or USB Cards are used for data storage. But any inappropriate action can result in creating unallocated space on USB card. Do not bother as multiple users experience it. In this guide, you will learn why this happens and how to fix it.

While accessing your USB drive, have you come across unallocated space on USB? Do not bother as multiple users experience it, but by the end of this guide, you will get to know how to fix it.

Here we will discuss what unallocated space is, the reason behind it, and how to fix it. Read on to learn about it.

What is Unallocated Space on a USB Flash Drive?

Unallocated space is the one that is not formatted and not partitioned too, so it is not available for data storage. In simple words, we can say that unallocated space on USB is useless and inaccessible. But how does space on the USB/SD card become unallocated? Let us see this in the next part.

Why Does an USB Card Suddenly Become Unallocated?

SD or USB Cards are used for data storage and are removable drives. But any inappropriate action can result in creating unallocated space on a USB card. Here are some of the possible causes of unallocated space on USB:

• While accessing it on any unsafe system, the chances of virus attack are high. If it happens, unallocated space can appear suddenly.
• Incorrect deletion of stored data or files can also be the cause of unallocated space on USB.
• While changing the USB card partition system or any unsuccessful partitioning can also lead to unallocated space.

Do not worry, whatever be the reason you can fix and repair this issue of unallocated space on USB. In the next part, we will discuss the methods that will help you fix it.

How to Fix and Repair Unallocated Space on USB Card

Now you know what is unallocated space on USB and how it forms. We will quickly move on to the solutions and learn how you can fix the issue easily.

If you are not losing any important data, then you can make unallocated space usable by creating a new partition with the following two ways. Proceed with them as guided below:

Method 1: Create New Partition with Disk Management

Step 1: Connect your SD card or USB with the system and open the Start menu.

Step 2: Proceed to My Computer or This PC and right-click on it. Select Manage.

Step 3: Click on Manage and then Disk Management, and you will see all the available drives on the system. Select your USB drive or SD card and right-click on it to reach the Delete Volume option. When prompted, click on Yes.

Step 4: Now again, right-click on your connected drive and select New Simple Volume.

Step 5: Follow the partition wizard to complete the process.

Once the wizard completes the process, restart your system and reconnect the drive to see if the issue is fixed.

Method 2: Create New Partition with DiskPart Command

You can also get back the lost or unallocated space with the DiskPart tool. Check out the detailed steps:

Step 1: Click on the Start menu, and in the search box or in the run box, type diskpart. Now, right-click on diskpart, and then click on the option Run as administrator.

Step 2: Type list disk and then press the Enter button to look for the connected USB drive number. You can confirm the right drive by looking at the drive size.

Step 3: Let's say the disk number is 2, type select disk 2 and press the Enter key.

Step 4: Type clean and press Enter. All the data on the selected disk will be deleted.

Step 5: Type create partition primary and press Enter. After the successful creation of the new partition, you will be able to use your USB drive without facing any unallocated space issue.

Step 6: At last, format the USB drive to you preferred file system. Type the following command and press Enter: format fs=fat32(or format fs=NTFS, you can modify the file system as your need).

Method 3: Restore the Partition Data from the Unallocated USB

While creating the new partition, if you accidentally lose any of your important data, Wondershare Recoverit Data Recovery software can help you in recovering your lost data. Here are the detailed steps for you:

Step 1: Connect USB drive with the system

Download and launch Wondershare Recoverit on your system and connect the respective USB drive from which you have lost your data.

Step 2: Select the connected drive

After launching the software and connecting the drive to the system, select it from all the listed drives on your computer.

Step 3: Begin the scan

After selecting the connected drive, click on the all-around scan to begin the scan. When the scanning is in progress, you can stop or even pause the scan or can locate your targeted files.

Step 4: Preview and the recover files

When the scanning completes, Wondershare Recoverit allows you to preview the recovered files before recovering and saving them.

Video Tutorial on How to Fix Unallocated Hard Drive on Windows

Recent Videos from Recoverit

View More >

The Bottom Line

You can get unallocated space on USB because of a number of reasons but fixing them is also possible. We have discussed the 3 methods to fix it. Follow them to fix the unallocated space on USB drive. However, if you lose any of your important data, then Wondershare Recoverit data recovery software allows you to get back your lost data easily.