Stop using the SD card immediately. Every write operation risks overwriting your files. Don't format, don't take new photos, don't save anything.

Step 1: Diagnose the Problem

Symptom	Cause	Fixable?
"The disk is corrupted"	File system damage	✅ Yes
Card not showing up	Driver/reader issue	✅ Usually
"You need to format" prompt	Corrupted file system	✅ Yes (recover first!)
0 bytes shown	Severe corruption	⚠️ Maybe
Card is read-only	Write protection	✅ Yes
Files visible but won't open	File corruption	✅ Separate repair needed

Step 2: Check Physical Connections

Before assuming the card is corrupted:

Try a different card reader — Built-in laptop readers often fail
Try a different USB port — Use a powered port, not a hub
Try a different computer — Rules out driver issues
Check for write protection — Some cards have a physical lock switch

If the card works on another computer, the issue is with your system, not the card.

Step 3: Recover Your Files First

Never format a corrupted SD card until you've recovered your files.

Option A: Windows File Recovery (Free)

Windows 10/11 includes a built-in recovery tool:

winfr E: D:\Recovered /regular

Replace E: with your SD card letter and D:\Recovered with your output folder.

Option B: PhotoRec (Free, Open Source)

Download PhotoRec
Run as administrator
Select your SD card
Choose file system type (usually FAT/NTFS)
Select destination folder (NOT on the SD card)
Wait for recovery to complete

Success rate: 70-90% for typical corruption

Option C: Recuva (Free)

Download Recuva
Run and select "In a specific location" → your SD card
Enable "Deep Scan" for better results
Recover files to a different drive

Always recover to a different drive — never save recovered files back to the corrupted SD card.

Step 4: Repair the SD Card

Once your files are safely recovered, you can fix the card:

Method A: Windows Error Checking

Open File Explorer
Right-click the SD card → Properties
Tools tab → Check → Scan and repair

Method B: CHKDSK (Command Line)

chkdsk E: /f

Replace E: with your SD card letter. The /f flag fixes file system errors.

Method C: Format (Last Resort)

Only format after recovering your files:

Right-click the SD card in File Explorer
Select Format
Choose:
- File system: exFAT for cards >32GB, FAT32 for smaller
- Allocation unit size: Default
- Quick format: Uncheck for thorough format
Click Start

Step 5: Repair Recovered Video Files

If your videos were recovered but won't play, they need repair:

Use VidRepair to fix corrupted video files recovered from SD cards:
1. Download VidRepair from vidrepair.com
2. Select the recovered video file
3. Add a reference file from the same camera if available
4. Click Repair
Why this works: SD card corruption often damages the video container (metadata), not the actual video data. VidRepair reconstructs this metadata.

When SD Cards Can't Be Fixed

Situation	Solution
Physical damage	Professional recovery service ($$$)
Controller failure	Professional recovery only
Severe NAND damage	May be unrecoverable
Encryption corruption	Usually unrecoverable

Preventing SD Card Corruption

Eject properly — Always use "Safely Remove Hardware"
Don't fill completely — Leave 10-20% free space
Use quality cards — SanDisk, Samsung, Lexar, Kingston
Replace old cards — SD cards wear out after ~10,000 write cycles
Avoid extreme temperatures — Heat kills flash memory
Don't remove during writes — Wait for camera to finish saving

SD Card Health Check

To check if your SD card is failing:

# Check for bad sectors (Windows)
chkdsk E: /r

The /r flag locates bad sectors and recovers readable data.

Fix Corrupted Video Files — Repair recovered videos
GoPro SD Card Recovery — Camera-specific guide
How Video Files Get Corrupted — Understand causes

How to Fix a Corrupted SD Card and Recover Your Files