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How to Reset a USB Flash to Normal Size

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  • April 28, 2014March 31, 2018
One of my USB flash was used as a boot drive for a machine, and the size was reduced from 2GB to about 300MB. In this post, we use command diskpart to restore it to normal size.

First of all, we enter the interactive mode of diskpart.
C:Usersed>diskpart
List all disks in the computer.
DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          120 GB      0 B
  Disk 1    Online          338 MB      0 B

Select disk 1 as the target disk.
DISKPART> select disk 1

Disk 1 is now the selected disk.

Clean and erase all data from the disk.
DISKPART> clean

DiskPart succeeded in cleaning the disk.

Create a primary partition for this disk without indicating the size.
DISKPART> create partition primary

DiskPart succeeded in creating the specified partition.

List all partitions in the target disk.
DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
* Partition 1    Primary           1967 MB    64 KB

Select partition 1.
DISKPART> select partition 1

Partition 1 is now the selected partition.

See the detail of this partition.
DISKPART> detail partition

Partition 1
Type  : 06
Hidden: No
Active: No
Offset in Bytes: 65536

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
* Volume 2     E                RAW    Removable   1967 MB  Healthy

The partition is not active so far, let's activate it.
DISKPART> active

DiskPart marked the current partition as active.

See the detail of this partition again.
DISKPART> detail partition

Partition 1
Type  : 06
Hidden: No
Active: Yes
Offset in Bytes: 65536

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
* Volume 2     E                RAW    Removable   1967 MB  Healthy

Now, we can format the disk with "ntfs" and "quick" option.
DISKPART> format fs=ntfs quick label="My USB Flash"

  100 percent completed

DiskPart successfully formatted the volume.

Let's see all disks.
DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          120 GB      0 B
* Disk 1    Online         1968 MB      0 B

Now, it's back.

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