How to restore USB drive back to full capacity

Insert USB drive

Access to MS-DOS command prompt

Microsoft DiskPart version 10.0.18362.1

Copyright (C) Microsoft Corporation.

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt

  --------  -------------  -------  -------  ---  ---

  Disk 0    Online          447 GB  1024 KB        *

  Disk 1    Online          931 GB  1024 KB        *

  Disk 2    Online         7680 MB      0 B

DISKPART> select disk 2

Disk 2 is now the selected disk.

DISKPART> delete partiton

Microsoft DiskPart version 10.0.18362.1

DISK        - Delete a missing disk from the disk list.

PARTITION   - Delete the selected partition.

VOLUME      - Delete the selected volume.

DISKPART> partition

Microsoft DiskPart version 10.0.18362.1

ACTIVE      - Mark the selected partition as active.

ADD         - Add a mirror to a simple volume.

ASSIGN      - Assign a drive letter or mount point to the selected volume.

ATTRIBUTES  - Manipulate volume or disk attributes.

ATTACH      - Attaches a virtual disk file.

AUTOMOUNT   - Enable and disable automatic mounting of basic volumes.

BREAK       - Break a mirror set.

CLEAN       - Clear the configuration information, or all information, off the

              disk.

COMPACT     - Attempts to reduce the physical size of the file.

CONVERT     - Convert between different disk formats.

CREATE      - Create a volume, partition or virtual disk.

DELETE      - Delete an object.

DETAIL      - Provide details about an object.

DETACH      - Detaches a virtual disk file.

EXIT        - Exit DiskPart.

EXTEND      - Extend a volume.

EXPAND      - Expands the maximum size available on a virtual disk.

FILESYSTEMS - Display current and supported file systems on the volume.

FORMAT      - Format the volume or partition.

GPT         - Assign attributes to the selected GPT partition.

HELP        - Display a list of commands.

IMPORT      - Import a disk group.

INACTIVE    - Mark the selected partition as inactive.

LIST        - Display a list of objects.

MERGE       - Merges a child disk with its parents.

ONLINE      - Online an object that is currently marked as offline.

OFFLINE     - Offline an object that is currently marked as online.

RECOVER     - Refreshes the state of all disks in the selected pack.

              Attempts recovery on disks in the invalid pack, and

              resynchronizes mirrored volumes and RAID5 volumes

              that have stale plex or parity data.

REM         - Does nothing. This is used to comment scripts.

REMOVE      - Remove a drive letter or mount point assignment.

REPAIR      - Repair a RAID-5 volume with a failed member.

RESCAN      - Rescan the computer looking for disks and volumes.

RETAIN      - Place a retained partition under a simple volume.

SAN         - Display or set the SAN policy for the currently booted OS.

SELECT      - Shift the focus to an object.

SETID       - Change the partition type.

SHRINK      - Reduce the size of the selected volume.

UNIQUEID    - Displays or sets the GUID partition table (GPT) identifier or

              master boot record (MBR) signature of a disk.

DISKPART> create partition primary

No usable free extent could be found. It may be that there is insufficient

free space to create a partition at the specified size and offset. Specify

different size and offset values or don't specify either to create the

maximum sized partition. It may be that the disk is partitioned using the MBR disk

partitioning format and the disk contains either 4 primary partitions, (no

more partitions may be created), or 3 primary partitions and one extended

partition, (only logical drives may be created).

DISKPART> clean

DiskPart has encountered an error: The device is not ready.

See the System Event Log for more information.

DISKPART> create partition primary

DiskPart succeeded in creating the specified partition.

DISKPART>

Source: https://www.youtube.com/watch?v=_TRWUJ1oZHc