How to fix- Pen drive is showing Unknown Capacity & Unable to Complete Format problems in Windows 10 , 11

Sometime when you are trying to format a pen drive on your computer you may face this error message “Windows was unable to complete the format“. For majority of the cases this error is caused by some corrupted file present in the flash drive. Follow this fix on your computer and the problem will be over very soon-

Fix- Format the pen drive from CMD-

Formatting the pen drive from Command Prompt after creating a partition will solve this issue for you.

1. Type “cmd” in the Search box beside the Windows icon, to open an elevated Command Prompt window.

2. Then right click on “Command Prompt” which appears on the elevated search result and then click on “Run as administrator“.


Cmd Search


3. To get an idea of the disk partitions on your drive, all you need to do is to copy-paste these two commands one-by-one and hit Enter to execute both of the commands sequentially on your computer.

list disk




4. Now, in the list of the disks, you will have to note the “Disk No” for the pen drive.

You can easily do this by looking at the “Size” of the disk as the size of the pen drive will be much lesser than that of the size of your HDD.

( Example-For us,  it is the “Disk 2” as the size of the disk is 28 GB).


Disk 2


To create a new partition in your pen drive, you need to create a primary partition and format it in the ‘Fat32‘ format.

5. To do so copy-paste and modify these commands in Command Prompt window one-by-one and hit Enter after each of them to format the drive on your computer.

select disk (your disk no.)
create partition primary
select partition (your disk no.)
format fs=fat32


All Other Commands


The formatting process will take some time. Wait till it shows 100%. Once the pen drive is formatted, close the Command Prompt window.

6. Remove the pen drive from your computer and then insert the pen drive to your computer.

You may need to format the pen drive manually again. Follow these steps to do so-

1. Press Windows key+E. 

2. Now, in the File Explorer window, on the left-hand side, click on “This PC“.


This Pc File Explorer


3. Now, right-click on your pen drive. After that, click on “Format” to start formatting the drive.


Format F


3. Then you need to click on “Start” to start the formatting process.


Start Format


Once the pen drive is formatted you can easily access it.

Your problem should be solved.

3 thoughts on “How to fix- Pen drive is showing Unknown Capacity & Unable to Complete Format problems in Windows 10 , 11”

  1. I loved how easily explained every step is. All my techie friends gave up on my Pendrive when I came across this article. Simply Mindblowing !!!

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