How to Fix Pen Drive Showing Less Space?

January 31, 2019

Many people find USB pen drive showing less space than actual after formatting or else. There's still a solution before throwing it.

Why pen drive showing less space?

The flash technology can get damaged easily if not used carefully. “Why my 16gb pen drive only shows 4mb now? How to fix?” one user asked. While a lot of people said they had encountered the same problem, too. Generally speaking, a pen drive showing less space happens in the situations like:

  • Removing the pen drive suddenly while it is working
  • Interruption before formatting completed or using some third-party software inappropriately
  • Installing bootable OS (operating system) such as Chrome or Linux. It will change the partition system of your pen drive so some free space will appear
  • Computer virus

Don’t be hurry to throw it away because there still exists a solution. That is cleaning. You can find how to deal with pen drive showing less capacity from the following article. Anyway, in order to avoid losing important data, please do backup first! By the way, AOMEI Backupper is capable to give a help.

2 solutions when pen drive showing less space

  • Use Diskpart

The most simple way is to use Windows Disk Management but Disk Management does not allow you to delete or format some system related files. Thus, it comes to another tool named Diskpart.

Step 1: Connect the pen drive to your computer.

Step 2: Search “Command Prompt” in the Start menu. Right click its shortcut and select “Run as administrator”.

Step 3: Type “diskpart” → Enter.

Type Diskpart

Step 4: Type “list disk” → Enter. It will show you disks connected to the computer.

List Disk

Step 5: Type “select disk #” → Enter. (Replace # with the number which is identified as the pen drive in your computer.)

Select Disk 2

Note: Be careful when entering the number, otherwise everything on the disk you choose will disappear.

Step 6: Type “clean” → Enter.

Clean Enter

Step 7: Type “create partition primary” after you see “Diskpart succeeded in cleaning the disk”. If you want to create more than one partition on the pen drive, specify the partition size by this syntax: create partition primary size=#. For example, to create a 4000MB partition, run the command “create partition primary size=4000”.

Create Partition Primary

When finish, leave the command window then you can format the pen drive easily through Disk Management as you wish. However, using Diskpart to solve USB drive shwoing less space takes certain risks, especially for computer green hands. It is inconvenient to distinguish which disk is exactly the pen drive. Besides, if typing something wrong in the command window, no one could guarantee what will happen next. So here introduce another useful freeware -- AOMEI Partition Assistant.

  • Use AOMEI Partition Assistant

AOMEI Partition Assistant is a freeware designed for better partition management. It applies to Windows 7/8/10. Compared with Diskpart, this program is much handier to operate.

Step 1: Download and install the software.

Step 2: Connect the pen drive to your computer. Launch Partition Assistant.

Step 3: Right click the removable device. Select Wipe Hard Drive.

Wipe Hard Drive

Step 4: Choose the first option "Fill sectors with Zero" and click OK. To use left three advanced options, please upgrade to Professional edition.

Fill sectors with Zero

Step 5: Click “Apply” for final execution.


With AOMEI, pen drive showing less space is just solved within a few of clicks. You don’t need to worry about one mistake that causes data loss, because before applying, you can revoke at any time. After wiping, Create Partition, Resize Partition as well as other features will also help you a lot, and you can even upgrade to AOMEI Partition Assistant Professional to get more advanced functions.