How to Repair and Restore Unallocated Space on USB/SD Card?

Tracy King updated on Dec 10, 2018 to Partition Manager | How-to Articles

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 in your PC? You can neither access data nor save new data on it.

When such a problem happened, most users would directly abandon the USB drive or SD card, thinking that the drive can never be repaired and nothing can be done!

If you are having the same thought, stop thinking so right now! Now the unallocated space error on a USB drive, SD card or memory card can be fixed on your own! How? Here below, we'll provide you effective methods to help you repair and fix this issue with simple steps now.

How to fix and repair USB/SD card showing unallocated error

Here you'll have two steps to go for repairing unallocated USB drive or SD card:

Step 1. Recover data from unallocated space on USB/SD card

To protect you from losing data on the unallocated USB drive or SD card, you shall first try a professional data recovery software to get your precious data restored in advance.

Here you may try EaseUS Data Recovery Wizard which supports you to recover data from unallocated USB drive/SD card within three simple steps:

Launch software > Select location and scan > Preview and restore.

Step 2. Repair unallocated USB/SD card

To restore unallocated space on the USB drive or SD card, you have two choices here:
1. Repair the unallocated USB/SD card with CMD
2. Restore unallocated space on USB/SD card with free partition manager software

You may selectively follow either one method to restore and repair unallocated space on USB/SD card and make your device reusable again.

Method 1. Repair unallocated USB/SD with CMD

  • Type: list disk and hit Enter;
  • Type: select disk 0 and hit Enter; (0 shall be the drive letter of your unallocated USB/SD card.)
  • Type: create partition primary and hit Enter;
  • After this process, type: exit and hit Enter to finish the process.
  • Go to your USB drive or SD card, right-click it and select "Format".
  • Set the file system and rename it for your USB drive or SD card then click "Start" to make it reusable again.

Method 2. Restore unallocated USB/SD card with free partition manager software

If you prefer a more straightforward way to repair unallocated USB or SD card, you may try free partition manager software - EaseUS Partition Master Free. 

Download Now

 Windows 10 is supported

This software allows you to restore unallocated USB/SD card within 3 simple steps. You may download it and follow below tutorial steps to get problem fixed now:

# 1. Wipe data on unallocated USB/SD card


Step 1: Launch EaseUS Partition Master, right-click the partition you want to erase data from, and choose "Wipe Data".

Wipe Partition - Step 1

Step 2: In the new window, set the time for which you want to wipe your partition, then click "OK".

Wipe Partition - Step 2

Step 3: Click the "Execute Operation" button in the top-right corner, check the changes, then click "Apply" to wipe the data on your partition.

Wipe Partition - Step 3

# 2. Create a partition on unallocated space in USB/SD card 

If you want to create a partition on an empty USB, SD card or external hard drive, connect it to your PC in advance.

Step 1: Launch EaseUS Partition Master

On the main window, right-click on the unallocated space on your hard drive or external storage device and select "Create".

Create partition on unallocated space

Step 2: Adjust the new partition size, file system, label, etc.

Set the size, partition label, drive letter, file system, etc. for the new partition and click "OK" to continue.

Set up new partition

Step 3: Confirm to create a new partition

Click on the "Execute Operation" button and confirm to create a new partition by clicking "Apply".

Confirm and keep all changes

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Frequently Asked Questions

Why Choose EaseUS Partition Master?

"I've used Partition Master Professional many times to create, delete, format, move, rename, and resize partitions."PCWorld

"Partitioning tools have come a very long since the days of complicated command line utilities and EASEUS Partition Master is one of the most advanced programs available."TECH ADVISOR

"I love that the changes you make with EaseUS Partition Master Free aren't immediately applied to the disks. It makes it way easier to play out what will happen after you've made all the changes."Lifewire

Will the "Migrate OS" feature transfer the Windows system files only or the whole C drive?

To ensure that the migrated system will boot normally, the Migrate OS feature will transfer all the files in the system and the boot partitions. Generally, the boot partition is the C drive so the transfer will include all the files in C.

Does EaseUS Partition Master license apply to multiple computers?

The license of Partition Master Professional and Server editions can be used on 1 computer only, while that for for the Technician and Unlimited editions can be used on multiple machines.

What is the difference between EaseUS Partition Master Trial version and the Free version?

Free is for home users only, with most basic functions available such as partition resize and clone. While trial can help you understand how this product works and test what a full license can do on a business or server OS machine.

Will it cause any data loss after resizing the partition in EaseUS Partition Master?

Generally, it will not cause any data loss or boot issue by resizing a partition. However, in order to protect your data, we suggest that you backup the partition before resizing, in case of any unexpected situations such as power outages, computer hardware failures, etc. You can use EaseUS Todo Backup to backup the partition and its trial version is fully functioned for 30 days.

What should I prepare before resizing the partition?

On the partition that is going to be operated, there might be some files being occupied by other programs. To ensure a successful operation, we suggest that you close all the unnecessary software before resizing that partition. Otherwise, EaseUS Partition Master will detect the partition being locked by the other software and require a reboot to resize the partition under boot mode.

About EaseUS Partition Master

All-round disk & partition management software for personal and commercial use. Let it manage your storage drive: resize, format, delete, clone, convert, etc.