Recover Lost Space on USB Drive

Suddenly missing space on USB drive after a format? You may find that all of the storage space on your USB drive has gone missing after using tools to burn an ISO to USB. Don't worry, you can easily recover that lost space on your flash drive, bring back the missing space to use for storage purposes, and successfully restore your USB back to its full usable capacity.

Why does USB Drive Storage Space go Missing?

You'll often find that you are suddenly missing space on a USB flash drive because the device has been reconfigured to be detected as a bootable ISO, instead of storage media. For example; by using tools like Etcher to Burn ISO to USB or any tool of this type that uses DD (Disk Dump) to RawWrite an ISO image to a USB device, its capacity then becomes reduced to the size of the ISO file.

Obviously this can pose a problem if the original capacity of your flash drive is much larger than the image used. When raw writing an ISO to USB, the device assumes the filesystem of the Image, and any remaining space on the device becomes unallocated. As a result, devices left in this state can no longer be used for traditional storage purposes.

To fix this you simply need to allocate the unused space to a new volume and partition. This new partition can then be used as a separate container for storage purposes, and accessed via an assigned drive letter.

The following assumes the user is running from a Windows operating environment. I will follow-up with the procedure for Linux users as well.

How to Recover Lost Space on USB Drive

To Recover Lost Space on USB Drive, and gain access to the missing storage space, you can perform the following simple steps;

  1. From the Windows Search box, type diskmgmt.msc and then press Enter. 
    diskmgmt.msc
  2. Next, (1) Locate your USB Disk from the list, (2) Right Click on the Unallocated Space and then select New Simple Volume.
    Create New Simple Volume in Unallocated Space
  3. When prompted, click Next to start the New Simple Volume Wizard.
    Create Simple Volume
  4. Now you can Specify Volume Size. Click Next to use all of the remaining space.
    Specify Size of New Volume
  5. Then you'll be asked to assign a Drive Letter. Click Next.
    Assign Drive Letter
  6. Finally, to Format and Create the Partition. (1) Select a Filesystem. (2) Create a Volume Label. (3) Click Next.
    Format and Create Partition
  7. Click Finish to complete the creation of the New Partition.
    Click Finish to create the partition and Recover Lost Space on USB Drive

If all went well you should now have access to the once missing space on your USB drive via the newly created volume and related assigned drive letter. This concludes how to recover lost space on USB Drives.