How to Fix USB Drive Incorrect Size Error on Windows 11: Step-by-Step Solutions

Sometimes when you plug in a USB drive on Windows 11, it may show an incorrect size. This can be confusing and prevent you from using the full storage capacity of your device. Fortunately, there are simple ways to fix this issue without needing advanced technical skills.

This guide will walk you through easy, step-by-step solutions to correct the USB drive size error. Each method is explained clearly, so you can follow along even if you are a beginner. Let’s get started and get your USB drive working properly again.

Fixing the USB size error often involves checking the drive’s partitions, formatting, or using Windows tools to reset the drive. We will start with the easiest solutions and move to more detailed steps if needed.

By the end, you should be able to see the correct size of your USB drive and use it normally on your Windows 11 PC.

Quick Note Before You Start

Before attempting any fixes, make sure to follow these quick checks:

Ensure your USB drive is properly connected to a working USB port.
Try plugging the USB drive into a different USB port or another computer to rule out hardware issues.
Back up any important data on the USB drive if possible, as some fixes might erase your files.
Check if the USB drive is recognized in Windows Explorer and Disk Management.

Step 1: Use Windows Disk Management to Check the USB Drive

Windows Disk Management is a built-in tool that helps you view and manage storage devices. It can show if your USB drive has unallocated space or incorrect partitions causing the size error.

Press Windows Key + X on your keyboard and select Disk Management from the menu.
In the Disk Management window, find your USB drive by looking at the size and drive letter.
Check if there are any partitions marked as Unallocated or if the total size shown matches your USB’s actual capacity.
If you see unallocated space, this could be why your drive shows the wrong size.

Understanding the layout here is important because sometimes USB drives have leftover partitions or corrupted formatting that need to be fixed.

Step 2: Format the USB Drive Correctly

Formatting the USB drive can fix size errors by creating a fresh partition that uses the entire storage space. Keep in mind, formatting will erase all data on the drive, so back up your files first.

Open Disk Management again as described in Step 1.
Right-click on your USB drive’s partition (or unallocated space if no partition exists) and choose Format.
In the format window, set the File System to NTFS or exFAT (exFAT is better for compatibility with other devices).
Make sure the Allocation unit size is set to default.
Give your drive a name in the Volume label field (optional).
Check the box for Perform a quick format and click OK.

After formatting, the USB drive should show the correct size and be ready to use.

Step 3: Use Diskpart to Clean and Repartition the Drive

If formatting via Disk Management doesn’t work, you can use the Diskpart tool. This is a command-line utility that can remove all partitions and reinitialize the drive.

Press Windows Key + S, type cmd, right-click Command Prompt, and select Run as administrator.
In the Command Prompt, type diskpart and press Enter.
Type list disk and press Enter. This will show all connected drives.
Identify your USB drive by its size. Be very careful to select the correct disk to avoid data loss on other drives.
Type select disk X (replace X with the USB drive’s disk number) and press Enter.
Type clean and press Enter. This will erase all partitions and data on the USB drive.
Type create partition primary and press Enter to create a new partition using the entire disk.
Type format fs=exfat quick and press Enter to quickly format the drive with exFAT file system.
Type assign and press Enter to assign a drive letter.
Type exit twice to close Diskpart and Command Prompt.

This method is powerful and resets the USB drive to a clean state, which usually fixes size errors caused by corrupted partitions.

Alternative Method: Use Third-Party USB Formatting Tools

If Windows tools do not resolve the issue, you can try third-party utilities designed for USB drives. Tools like Rufus or HP USB Disk Storage Format Tool offer advanced options for formatting and repairing USB drives.

These programs often provide easier interfaces and additional features such as repairing corrupted file systems or creating bootable drives.

Frequently Asked Questions (FAQs)

Why does my USB drive show less storage than advertised?

This is often due to hidden or corrupted partitions, formatting issues, or the difference between how manufacturers calculate size and how Windows reports it. Fixing partitions or formatting the drive usually helps.

Will formatting my USB drive erase all my data?

Yes, formatting deletes all files on the drive. Always back up important data before proceeding with formatting.

Can I recover files from a USB drive showing incorrect size?

It might be possible using data recovery software, but success depends on the level of corruption. Avoid writing new data to the drive before recovery.

Is it safe to use Diskpart to fix my USB drive?

Yes, but you must be very careful to select the correct disk. Diskpart commands are powerful and irreversible, so double-check the disk number before executing commands.

Why does my USB drive show up as raw or unallocated?

This usually means the file system is damaged or missing. Formatting or using Diskpart to clean and repartition the drive can fix this.

When Nothing Works

If none of the above methods fix the USB drive size error, the problem might be hardware-related. The USB drive itself could be faulty or damaged. Here are some final steps to consider:

Try the USB drive on another computer to confirm if the issue persists.
Check for firmware updates for your USB drive if available from the manufacturer’s website.
Contact the USB drive manufacturer’s support for help or warranty replacement options.
Consider professional data recovery services if your data is critical and inaccessible.

For official Microsoft support, visit the Windows Support page for more troubleshooting guides.

Conclusion

USB drive incorrect size errors on Windows 11 can usually be fixed by checking partitions with Disk Management, formatting the drive, or using Diskpart to clean and recreate partitions. These steps help resolve issues caused by corrupted partitions or formatting problems.

Always start with the simplest methods and back up your data before making changes. If needed, third-party tools and professional support are available as alternatives.

With these solutions, you should be able to restore your USB drive’s correct capacity and use it without any size errors on your Windows 11 computer.