When you wish to format your USB flash drive or micro SD card and Windows shows you the message – “Windows was unable to complete the format“, it can get really annoying and frustrating. The worst is that this error doesn’t tell you why format did not complete successfully. Nor does it tell you what you have to do next to fix the issue. Turns out Windows failing to format the Pen drive or hard disk is quite a common issue and like every other Windows problem, this one too has a solution. Before we dive into the solutions for Windows was unable to complete the format error, it is better to understand why the problem occurs in the first place.


windows was unable to complete the format

Why Windows was Unable to Complete the Format?

There could be multiple reasons why Windows is showing this annoying message. The most common four reasons are as follows –

1. USB Drive infected with malware/virus

Whenever your USB or external hard disk is infected with a virus, chances are that the virus has actually corrupted the disk file system, preventing the OS from formatting the disk. If you don’t want to run into this problem again, make sure your USB drive and hard disk stay free from virus and other malware.

2. Enabled Write-protection

If the external hard drive / SD Card you are trying to format is ‘Write protected,’ then it explicitly prevents Windows from formatting the disk.

3. Damaged sectors

Whenever a sector on the media storage device is damaged, it prevents Windows from formatting the storage device. Files that are stored on the USB drive or hard disk usually occupy sectors that are not continuous. Bad/damaged sectors cannot be written to and Windows complains about this with the annoying message – Windows was unable to complete the format.

4. Physical damage

If your USB drive or the hard disk has suffered physical damage, chances are Windows will never be able to use the device. Sometimes, when you drop your hard disk down, the impact damages the circuitry inside. This can lead to improper functioning.

Now that we understand the reasons why Windows fails to format your USB drive or hard disk, let’s take a look at the solutions that will help you resolve this issue once and for all!

How to fix Windows was Unable to Complete the Format

Unless your USB drive is damaged physically to a very bad extent, the solutions that are presented here should help you format your USB drive or hard disk without any issues. The first thing that you should try is formatting using Disk Management.

Note: We are using Windows 10 to perform these methods. However, these methods also work on other Windows versions including Windows 7 and Windows 8.

1. How to Format Hard Drive Using Disk Management

If the traditional formatting method fails with Windows displaying the error “Windows was unable to complete the format“, then disk management can help you to format the disk successfully. Disk Management comes as part of Windows by default and helps you create a new volume, delete or format disk partitions, change drive letters and so on. What we are interested in is the format capability of Windows Disk Management system. To use this feature, follow these steps –

Step 1: Right-click on This PC (Windows 10) or My Computer (older versions of Windows) and select ‘Manage‘.

Windows was unable to complete the format micro sd card

Step 2: In the Next Window, select Disk Management. Then right-click the external hard drive/pen drive that you want to format. Click “Format”

Windows was unable to complete the format external hard drive

Step 3: Select the file system in the next window, and click OK.

Windows was unable to complete the format pendrive

When the process is complete, you will see that the drive has been successfully formatted. If this doesn’t fix the issue, try Method 2.

2. How to Clean and Format Hard Drive Using DiskPart

Sometimes, the command prompt can be used to solve annoying issues. But this requires a basic understanding of command prompt usage. If you are not familiar with the command prompt, we advise you to proceed with caution.

Step 1: Open Command Prompt as an administrator. You can search “Cmd” in the search bar and then right-click “Command Prompt” and select “Run as an administrator.”

Step 2: In the command prompt copy-paste the command given below and press Enter. [Ref. Image 1]


Windows was unable to complete the format external drive, micro sd card, pendrive
Image 1: How to Format Drive using Diskpart on Windows 10

Step 3: Now type the command given below and press Enter. It will show the list of Drives on your PC. [Ref. Image 1]

list disk

Step 4: In the next command, we will select the drive which we need to format. It is suggested to cross-check the drive before selecting it. A wrong selection could result in important data loss.

If you wish to format the disk named ‘Disk 1’ from the list, type below command and press Enter. [Ref. Image 1]

select disk 1

Step 5: Now your desired drive is selected for clean up and format. To clean the corrupted storage drive, copy-paste below command and hit Enter. [Ref. Image 1]


Step 6: After clean the device, we will create the partition on the selected drive. Type below command and press Enter. [Ref. Image 2]

create partition primary

Windows was unable to complete the format external hard drive pen drive
Image 2: How to Format Drive using Diskpart on Windows 10

Step 7: We now have created the partition, so in the next command, we will select the created partition. Paste the below command and hit Enter. [Ref. Image 2]

select partition 1

Step 8: After selecting the partition, we will mark the partition as active before running the Format command. So type the below command and press Enter key. [Ref. Image 2]


Step 9: After marking the drive (your SD Card or Pendrive or other hard drive) as active, we are now ready to format the drive using Diskpart. Copy the below code and paste it in Command Prompt. Then hit Enter. [Ref. Image 2]

format FS=NTFS label=Mobipicker-Drive quick

This command will format the selected drive. In this command, I have selected the quick format with an NTFS file system. Mobipicker-Drive will be the name of the drive after format. You can modify it as per your preference.

Using the DiskPart, you can format the micro SD/pen drive in no time. If this method also doesn’t help with the error Windows was unable to complete the format, try out next solution.

3. Format Hard Drive Using Third-Party Software

There are many tools available that will allow you to format USB drives or hard disks without you having to go through all the technical details like entering commands in command prompt and stuff. EaseUS Partition Master will help you format disks easily. It comes with free trial options, which you can make use of to fix some really bad annoying formatting issues.

Conclusion: Windows was unable to complete the format

More often than not, the first two methods will resolve the Windows was unable to complete the format problem. If not, you can always try one of the several tools available online. Most of these tools are pretty straightforward to use and by just following the on-screen instructions, you should be able to resolve formatting errors. If you still face problems to format pen drive or micro SD card or other external hard drives, comment below with complete error details and we will help you.


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