Recovering lost data from a corrupted flash drive can seem daunting, but with the right tools and techniques, the process is very doable. When a flash drive becomes corrupted, the file structure and allocation tables get damaged, making it impossible for the operating system to access the stored data. However, the actual data usually remains intact until it gets overwritten by new content.
So as long as you act quickly and avoid using the flash drive, you have a very good chance of recovering your files. The key is to use data recovery software that can scan the drive and rebuild its file structure so you can copy the retrieved data to another device.
This guide will walk you through the steps and best practices for recovering data from a corrupted flash drive on Windows and Mac computers. We will cover:
What causes flash drive corruption and data loss
Flash drives are handy for transferring files between computers and storing data on the go. But they are susceptible to corruption and physical damage due to their compact build and lack of internal mechanisms to prevent data loss. Some common causes of USB flash drive corruption include:
- Improperly ejecting the flash drive before removing it from a computer
- Power outages or unplugging the drive during a transfer or write operation
- Bad sectors on the flash storage chips inside the drive
- Virus infections that damage the file system or partition table
- Physical damage from drops, moisture, high heat etc.
These problems can damage the flash drive’s file system, controller chip or storage media – leading to corrupted data, unreadable drive and lost files. When this happens, avoid using the affected drive right away. The more you use a corrupted drive, the lower your chances of data recovery.
How to recover data from a corrupted flash drive
When dealing with a corrupted flash drive, follow these general steps and best practices:
1. Stop using the affected flash drive immediately
As soon as you realize your flash drive is corrupted or notice read/write errors, unplug it from your computer. Avoid saving new files or copying data to/from the damaged drive as it could overwrite your stored data making it unrecoverable.
2. Try plugging the flash drive into another port or PC
Sometimes, the USB port you are using to connect the flash drive may be dusty or damaged itself. Try plugging the corrupted drive into another USB port or a different computer. If it works on another PC, copy your important files off the drive immediately.
3. Scan for errors to assess the extent of damage
Run the CHKDSK utility on Windows or First Aid on Mac to assess the level of corruption. This can help identify problems like bad sectors so you know the likely cause of the issue.
4. Use data recovery software to extract files
Specialty data recovery apps are able to dig deep and recover data from corrupted drives. We’ll cover the best software options for Windows and Mac later in this article.
5. Send to a pro if DIY recovery fails
For severe cases of physical media damage or very valuable lost data, consider using a professional data recovery service if your attempts are unsuccessful. Though pricey, pros have specialized tools to rebuild damaged drives.
How Flash Drives and Storage Media Work
To fully understand drive corruption, it helps to know how flash drives store data. We’ll do a quick overview of how flash memory works and where problems can occur.
Flash memory architecture
Flash drives use NAND flash memory chips to store data. These non-volatile chips retain data even when power is cut off. Inside the chips are:
- Storage cells organized in rows and columns in a grid pattern.
- Tunnel oxide layer that traps electrons to represent the 1s and 0s of binary data.
- Control circuitry to manage the writing or reading of voltages.
When power is applied, the trapped electrons can be read as stored data bits. NAND flash writes and erases data in blocks versus individual bits.
How data gets damaged
During normal operation, flash drives use a controller chip paired with firmware to manage the actual NAND flash memory. The controller handles:
- Reading/writing data when the OS makes requests
- Wear leveling to distribute writes across many cells
- Bad block mapping to avoid using damaged storage areas
- Error checking and correction code (ECC)
Problems arise when the controller or flash memory itself gets physically damaged due to mishandling, age or defects. Electrical shorts, failed blocks, corruption of the ECC data can make data unreadable. The file structure can also get damaged if the drive isn’t ejected before removal.
Risks of data overwriting
When a flash drive begins malfunctioning, often the only way to recover the data is via specialized software before it gets overwritten by new content. Hence it’s crucial to stop using the drive immediately and not attempt normal software repairs which could overwrite stored files before recovery is attempted.
Best Data Recovery Software
When logical errors cause filesystem corruption or partition tables to be erased, the drive will appear empty when plugged in. But the stored files are usually still recoverable by data recovery apps designed to restore even formatted or deleted files.
Here are some of the top data recovery programs available for Windows and Mac:
Windows
1. Disk Drill
Disk Drill can recover lost files from healthy drives as well from formatted, deleted or corrupted partitions. It features convenient capabilities like:
- Quick and deep scan modes
- Scans internal and external drives
- Previews files before recovery
- Retrieves up to 500MB free
Disk Drill is excellent for flash drive recovery on Windows.
2. Recuva
Another free recovery app for Windows is Recuva. It supports FAT, exFAT and NTFS drives. Key features include:
- Wizard-guided interface
- Deep scan capability for corrupted drives
- Retrieves a wide range of file types
- Can recover overwritten files in some cases
Recuva is easy to use with basic recovery needs. But the free version lacks certain advanced capabilities.
3. EaseUS
The Data Recovery Wizard from EaseUS is a popular premium option for Windows. It provides features like:
- Cloning utilities to avoid data overwriting
- Support for RAW drive recovery
- File previews before restoration
- Hardware issues detection
EaseUS provides extensive functionality for severe cases of drive corruption and physical damage.
Mac
Here are some top data recovery apps for Mac:
1. Disk Drill
Disk Drill is available for Mac OS as well with the same great features. It can scan internal or external drives and has quick and deep recovery modes. Flexible scanning filters and previewing of files before recovery make it easy to retrieve needed data.
2. Data Rescue
Data Rescue is a longstanding Mac recovery app for cases of severe data loss. It provides:
- Multiple scan options
- Recovery vault to prevent overwriting
- SMART drive health monitoring
- Cloning for backups
Data Rescue works great when Disk Utility can’t access an external drive or recover deleted files.
3. Stellar Data Recovery
Stellar Data Recovery offers a file repair option in addition to formats like HFS, APFS and encrypted volumes. Other highlights include:
- SMART drive status checks
- Preview files before recovery
- Supports Time Machine backups
- Creates bootable media
Stellar provides another quality choice for Mac recovery needs beyond basic file restoration.
Using Data Recovery Software
While features vary across apps, the general process to recover data from a corrupted drive involves:
Step 1) Install and launch the program
Install and open your selected recovery app after ensuring the corrupted flash drive isn’t connected. Some software offers a bootable media for when the operating system won’t load.
Step 2) Have it scan the flash drive
Shut down any other programs. Connect the flash drive to your computer and let the recovery app run a scan on the drive. This may take a while for a full scan. Avoid using the computer during the process.
Step 3) Preview and select files for recovery
The software will display recoverable files when the scan finishes. Browse and preview found items, then check those you want to restore. Avoid recovering to the same drive to prevent data overwriting.
Step 4) Choose a location to save the retrieved files
Select where you want to save the recovered data, like another drive, external media or cloud storage. Then let the recovery app restore your selected files.
Step 5) Check the recovered data
Once the recovery process completes, open the restored files to check they have the correct, usable data. You may need to try several scans with different options for maximum recovery from a severely corrupted drive.
DIY Flash Drive Repair Techniques
Before turning to data recovery apps, there are some DIY troubleshooting steps you can try when dealing with a corrupted flash drive:
Plug Into a Different USB Port
Try connecting the misbehaving flash drive into another USB port on your computer. A damaged port itself can sometimes cause connection issues with devices.
Run Antivirus Software
Virus infections that spread via flash drives can sometimes cause corruption. Run a full antivirus scan to check for and clean up any malware. Just be very careful about what you delete.
Format the Flash Drive
Formatting completely erases all data on a drive. But it also rebuilds the filesystem and clears out any corruption. Back up your files first just in case.
Use Disk Utility First Aid
The error checking tools in Disk Utility on Mac or CHKDSK on Windows can attempt basic drive repairs and mark bad sectors. This is worth trying before data recovery software.
Clean the USB Connector
If the drive isn’t being recognized at all, inspect the USB plug connector for any material blocking the contacts like dust or debris. Clean carefully using isopropyl alcohol.
Check for Physical Damage
Look over the exterior and connections of the flash drive for any signs of physical damage. Cracks, dents, bent pins or corrosion can cause data errors and connection failures.
When to Use a Professional Service
While data recovery software can address many corruption issues, severe physical damage often requires professional help. Consider a specialized data recovery service when:
- DIY software solutions fail completely
- The flash media has visible damage
- Critical business or personal data is inaccessible
- Normal disk repair tools cannot access the files
Pros have access to advanced tools like:
- PCB component replacement
- Flash memory chip transplant
- Clean room data extraction
- Specialized disk analysis and repair tools
This level of drive hardware and low-level disk repair is usually beyond the average home user. Data recovery services are expensive but can sometimes recover data even from drives with failed controller chips or severe NAND flash damage.
Preventing Flash Drive Corruption
You can help avoid many common causes of flash drive corruption and failures by:
- Ejecting and safely removing drives before disconnecting them
- Keeping drives away from moisture, heat and physical impacts
- Regularly backing up your data to another location
- Using quality drives from reputable manufacturers
- Scanning drives for errors and bad sectors periodically
- Avoiding file transfers during power failures or low battery
Practicing such precautions will minimize your risks of a damaged drive and data loss. But a corrupted flash drive doesn’t necessarily mean your files are gone forever. With the right recovery process, you can often get back lost documents, photos, videos and other content from even severely corrupted drives in many cases.
Conclusion
Flash drive corruption can happen unexpectedly, but don’t panic. By avoiding further use of the affected drive and using data recovery software quickly, you stand an excellent chance of restoring your files. Apps like Disk Drill make it easy to recover deleted and lost data from external drives, even if they have become completely unreadable.
In severe cases of physical damage, contacting a professional recovery service may be your best chance to get critical files back. The key is acting fast before anything has a chance to overwrite your stored data. Following a few basic precautions can also go a long way towards preventing many instances of flash drive corruption happening in the first place.