How to restore corrupted files on a flash drive

​USB flash drives are incredibly convenient tools for transferring and storing data on the go. Whether it’s a college assignment, critical work document, travel photos, or portable app installers, we rely on these tiny devices for a range of everyday tasks. However, flash drives are not immune to issues chief among them being file corruption. One moment, everything looks fine; the next, you can’t open your files or even access the device at all.

The device is removed during a file transfer.

Power is cut while writing data.

The flash drive is infected with malware or viruses.

The file system becomes damaged (e.g., FAT32. exFAT, NTFS).

There are bad sectors or physical wear on the flash memory.

You used the drive on incompatible or improperly ejected systems.

Corrupted files may appear missing, refuse to open, or trigger error messages such as:

“The file is damaged and cannot be opened.”

“You need to format the disk before using it.”

“Location is not available.”

“Invalid file format” or “File is unreadable.”

The good news? Many of these issues can be resolved with recovery tools or repair methods—without wiping the drive.

Step 1: Stop Using the Flash Drive

The moment you suspect corruption, stop using the USB drive. Continuing to write data or run scans from the same drive risks overwriting damaged files, making them unrecoverable. Safely eject it from your current system and avoid formatting or saving new files to it.

Step 2: Try Plugging Into Another USB Port or Computer

Sometimes, what seems like a corrupted flash drive is actually a connection issue. Try the following:

Use a different USB port (preferably USB 2.0 and USB 3.0 if available).

Connect the flash drive to another computer.

Avoid using USB hubs or extension cables.

If the files show up and work properly, the problem may be with the port or computer rather than the drive itself.

Step 3: Scan the Drive for Errors Using Built-In Tools

On Windows:

Windows includes a built-in tool called Check Disk (chkdsk) that scans drives for file system errors and attempts to fix them.

How to Use Check Disk:

Insert the USB flash drive.

Open Command Prompt as Administrator.

Type the following command:

bash

CopyEdit

chkdsk E: /f /r /x

(Replace “E:” with your actual flash drive letter.)

/f fixes errors

/r locates bad sectors and recovers readable data

/x forces the drive to dismount before scanning

Let the process complete. If successful, Windows may automatically recover readable portions of corrupted files or move them into a FOUND.000 folder with .chk extensions. You can rename and test these recovered files individually.

On macOS:

Insert your USB drive.

Open Disk Utility.

Select the flash drive from the list.

Click First Aid and then Run.

This checks and attempts to repair the file system. If macOS reports that it repaired the drive, try accessing the files again.

Step 4: Use File Recovery Software

Panda Assistant

Flash drives are essential tools for storing and transferring files, but they’re also vulnerable to corruption. Whether caused by an unexpected removal, virus infection, file system errors, or power loss during file transfer, corrupted files can seem impossible to recover. Fortunately, Panda Assistant offers a reliable and user-friendly solution for restoring corrupted files from flash drives quickly and effectively.

When files on a USB drive become corrupted, they often appear unreadable or inaccessible. However, the underlying data may still exist on the drive. Panda Assistant uses powerful scanning algorithms to locate and recover these damaged files—even if they don’t appear in your file explorer or trigger error messages when opened.

How Panda Assistant Helps:

Quick Setup: Install Panda Assistant on your computer (not on the corrupted flash drive) to avoid overwriting recoverable data.

Device Detection: Insert your flash drive, and the software will automatically recognize the storage device.

Deep Scan Mode: Choose the deep scan feature to search every sector of the flash drive for recoverable files, even those that are corrupted or hidden.

File Preview: View the found files to assess their condition before restoring.

Safe Recovery: Save recovered files to a separate location on your computer to ensure safety and prevent further damage.

Step 5: Format the Drive Only If Necessary (Last Resort)

If your drive is still unreadable, and all recovery efforts have failed or are complete, you may need to format the drive to make it usable again. This erases all data, so do it only after you’ve recovered everything possible.

On Windows:

Go to This PC.

Right-click the USB drive and choose Format.

Select FAT32 or exFAT as the file system.

Uncheck Quick Format if you want a more thorough refresh.

Click Start.

On macOS:

Open Disk Utility.

Select the USB drive.

Click Erase.

Choose exFAT or MS-DOS (FAT).

Name the drive and confirm.

After formatting, you can reuse the flash drive for new files. Consider keeping backups of anything important stored on it going forward.

Step 6: Use a Hex Editor for Advanced Recovery

For technically inclined users, a Hex Editor can help you analyze raw file data on the USB and recover parts of corrupted files manually.

Tools like:

HxD (Windows)

Hex Fiend (macOS)

010 Editor (cross-platform)

allow you to inspect binary content of files, find known headers (e.g., JPEG headers: FF D8 FF), and copy segments into a new file manually. This is time-consuming but can be valuable for partially corrupted data.

Step 7: Check for Malware or Viruses

Sometimes, flash drives are corrupted because of malware or worms that hide or encrypt files. Use a trusted antivirus or anti-malware tool to scan the flash drive:

Windows Defender

Malwarebytes

Avast

Bitdefender

Infected drives might:

Hide files and replace them with shortcuts.

Prevent access to folders.

Spread malicious scripts or files when opened.

After cleaning the device, you might be able to recover hidden files by changing folder view options:

Open File Explorer.

Go to View > Show > Hidden items.

Check Folder Options > View and disable “Hide protected operating system files.”

This may reveal hidden data, especially if the malware merely altered file attributes.

Step 8: Restore from a Backup (If Available)

This might sound obvious, but don’t forget to check any backups you’ve made:

External backup drives

Cloud backups like Google Drive, Dropbox, OneDrive

Backup software like Acronis, Macrium Reflect, or Time Machine

Even if the version isn’t the most recent, a backup might save you hours of effort.

Step 9: Send the Flash Drive to a Professional Recovery Lab

If the flash drive is physically damaged—bent, unrecognized, making strange noises, or completely dead—your only chance might be a professional data recovery service. These companies use cleanroom environments to open and repair the flash drive’s memory chips and controllers.

Top recovery labs include:

DriveSavers

Ontrack

Gillware

CBL Data Recovery

The cost for professional recovery varies widely, depending on the complexity and urgency. Many labs offer free evaluations and “no data, no charge” policies.

Tips to Avoid Flash Drive Corruption in the Future

Once you’ve gone through the ordeal of recovering corrupted files, you’ll want to avoid it happening again. Follow these best practices:

Always eject the drive properly using “Safely Remove Hardware” (Windows) or “Eject” (macOS).

Avoid using the drive during power outages or on unstable systems.

Don’t remove the USB mid-transfer of files.

Scan the drive regularly for malware.

Back up files stored on USB drives to other locations (external hard drive or cloud).

Use high-quality USB flash drives from reputable brands.

Avoid using flash drives for long-term storage they’re meant for portability, not archiving.

A corrupted flash drive doesn’t have to mean disaster. With the right tools, a bit of patience, and fast action, it’s possible to recover your files sometimes completely. From built-in repair tools like CHKDSK or Disk Utility to powerful third-party recovery programs and even professional labs, you have options at every level of technical skill and severity.

Just remember: stop using the flash drive immediately once you notice something’s wrong. Every second counts when it comes to data recovery. And once your files are safe again, consider this a wake-up call to implement a strong backup routine. Flash drives are helpful, but no storage device is perfect. Protect your data so you’re never caught off guard again.