Summary

This guide helps you troubleshoot and resolve: How to recover files from a failed or unreadable SD card or USB flash drive. Follow the steps below to fix the issue.

Common Causes

SD cards and USB flash drives are convenient for storing and transferring files, but they can fail unexpectedly due to physical damage, file system corruption, or accidental formatting. The good news is that in many cases, your data can still be recovered using built-in operating system tools or reputable third-party recovery software. This guide walks you through the safest methods to retrieve your files before attempting any repairs or formatting.

Quick Fix Steps

1. Stop using the drive immediately to prevent overwriting recoverable data.
2. Try the drive in a different USB port or card reader, or on another computer.
3. Check Disk Management (Windows) or Disk Utility (macOS) to see if the drive is detected.
4. Run the built-in repair tools (chkdsk on Windows, First Aid on macOS).
5. If the drive is detected but files are missing, use recovery software such as Recuva, PhotoRec, or Disk Drill.
6. If the drive is not detected at all, try data recovery software that supports raw or deep scans.

Before You Begin

• Do not save any new files to the affected drive.
• Have a separate storage destination ready (another USB drive, external hard drive, or cloud storage) with enough free space to hold the recovered files.
• Disconnect any other unnecessary USB devices to avoid confusion about drive letters or mount points.
• If the data is business-critical and you are unsure, open a ticket with our support team before attempting recovery.

Detailed Instructions

Step 1: Confirm the Drive Is Detected

Windows 10 or 11:

1. Connect the SD card or USB drive.
2. Press Win + X and select Disk Management.
3. Look for the drive in the lower pane. Note the drive letter and whether the partition shows as RAW, Unallocated, or Healthy.

macOS:

1. Connect the SD card or USB drive.
2. Open Disk Utility (search via Spotlight with Cmd + Space).
3. Select the drive from the sidebar and check whether it mounts and whether the file system is reported as readable.

Step 2: Try the Built-In Repair Tools

Windows (chkdsk):

1. Open Command Prompt as Administrator (search for cmd, right-click, choose Run as administrator).
2. Type chkdsk E: /f /r, replacing E: with your drive letter.
3. Press Enter and allow the scan to complete. Recovered files will be placed in a found000 folder or similar.

macOS (First Aid):

1. Open Disk Utility.
2. Select the affected drive (not the volume underneath it).
3. Click First Aid, then click Run.
4. When finished, click Show Details to review any errors found.

Step 3: Recover Files Using Software

If the built-in tools cannot read the file system, recovery software can scan the raw sectors of the drive and reassemble files.

Recommended tools:

• Recuva (Windows, free for personal use) — simple interface, good for documents and photos.
• PhotoRec (Windows, macOS, Linux, free and open source) — excellent for photos, videos, and documents; works on many file systems.
• Disk Drill (Windows, macOS, free tier available) — polished interface with deep scan capability.
• TestDisk (Windows, macOS, Linux, free and open source) — powerful partition and file system recovery, command-line based.

General recovery workflow:

1. Download and install the recovery tool on a different drive than the one you are recovering from.
2. Launch the tool and select the affected SD card or USB drive.
3. Choose a recovery destination on a separate drive with sufficient free space.
4. Start a scan. A deep scan takes longer but finds more files.
5. Preview recoverable files where possible and select the ones you need.
6. Save the recovered files to the separate destination.

Step 4: Recover From a RAW or Unallocated Partition

If the drive shows as RAW in Disk Management or unmountable in Disk Utility, the file system is damaged but the data may still be present.

Windows:

1. Open Disk Management and confirm the partition is RAW.
2. Do not format the drive.
3. Run a recovery tool such as TestDisk to rebuild the partition table, or use Recuva or Disk Drill to perform a deep scan on the RAW partition.

macOS:

1. Open Disk Utility and select the drive.
2. Click Mount. If it fails, do not click Erase.
3. Use Disk Drill or another macOS-compatible recovery tool to scan the unmounted drive.

Step 5: Address Card Reader and Write-Protection Issues

Sometimes the card itself is fine but the reader is the problem.

• Test the SD card in another device that has a built-in reader (camera, phone with OTG support, another computer).
• Check the small Lock switch on full-size SD cards. If it is slid to the locked position, the card will appear read-only or unreadable.
• For microSD cards in an adapter, ensure the adapter's lock switch is in the unlocked position.
• Try a different USB cable or a different USB flash drive in the same port to isolate whether the port is faulty.

Troubleshooting

The Drive Is Not Detected Anywhere

• Test the drive on a second computer to rule out a port or driver issue.
• On Windows, open Device Manager, expand Disk drives, and check for any device with a yellow warning icon. Right-click and choose Update driver.
• On macOS, open System Information > USB and see if the device appears when connected.
• If the drive still does not appear, the controller or memory may have failed. Professional recovery may be required.

Files Recovered But They Will Not Open

• The file may be partially overwritten or fragmented. Try a different recovery tool, as each one uses different reconstruction logic.
• For photos, try opening them in a different viewer (such as Google Photos, IrfanView, or Preview on macOS).
• For documents, use the repair feature in the originating application. For example, Microsoft Word and Excel both offer built-in document recovery options that can repair partially corrupted files.
• For videos, tools such as VLC or HandBrake can sometimes play or remux files that other players reject.

Recovery Software Cannot See the Drive

• Confirm the drive is listed in Disk Management or Disk Utility before launching the recovery tool.
• Run the recovery software as Administrator on Windows so it has permission to access raw devices.
• On macOS, grant Full Disk Access to the recovery application in System Settings > Privacy & Security > Full Disk Access.
• If the tool still cannot detect the drive, the storage media may have a hardware fault and professional recovery is the safest next step.

Preventing Future Data Loss

• Always eject SD cards and USB drives safely before removing them.
• Keep at least two backups of important files, using different media (for example, an external drive plus a cloud service).
• Replace SD cards that are several years old or have been used heavily, as flash memory wears out over time.
• Avoid using the same USB drive across multiple operating systems without safely ejecting it each time.

Still Having Issues?