Emergency · write-protected memory card
SD card became read-only after an error
Why did my SD card suddenly become read-only?
Short answer
Usually for one of two reasons: the reader honours the lock switch on the card or adapter, or the controller has forced read-only mode after detecting failing flash. Check the switch first. If the controller locked it, copy or image everything readable right away, then retire the card for good.
The situation
The card can be read but no longer accepts changes after a recording or copy error.
A card that still reads but refuses every write has either been locked mechanically or has locked itself. The difference matters: a switch can be flipped back, while a controller that went read-only after detecting failing flash is telling you the card is at the end of its life.
01 / Diagnose
Work out what actually disappeared
Full-size SD cards and SD adapters carry a small lock tab on the left edge, and readers honour it; microSD cards have no such switch, so a locked microSD is always the adapter. If the tab is up and the card still refuses writes, the controller has switched to read-only mode after write failures, typically when spare blocks ran out. That state cannot be reset.
A reader may honor the lock tab, or the controller may force read-only mode after detecting flash failure.
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Look at the lock tab on the card or on the microSD adapter and slide it away from the contacts before anything else.
- 2
Treat the read-only state as an opportunity rather than a fault: nothing can overwrite the recordings while the card refuses writes.
- 3
Copy everything readable to a computer disk straight away, largest and most important files first, before the card degrades further.
- 4
Then image the card or scan it read-only for anything deleted, and retire the card once the copies are verified.
Do not chase the registry keys, terminal commands or manufacturer utilities that promise to clear write protection. On a controller-locked card they achieve nothing, and on a working card they can start a format that wipes the very files you still need.
03 / Choose the method
Match the tool to the source
For stable, readable exFAT, NTFS and FAT16/FAT32 or uncompressed IMG, DD, RAW and BIN images.
Unconfirmed exports are marked .UNVERIFIED.
A read-only card cannot be brought back into service, and no software changes that: the decision was made in its controller. File Recovery Hero only reads sources anyway, which suits this situation, but it cannot restore the card's ability to record.
04 / Verify
Check the recovered content, not just its name
Compare the file count and total size on the destination with what the card shows, and open a sample from the beginning, the middle and the end of the copy. A card in controller-enforced read-only mode often returns errors in specific regions, and those files are the ones that fail.
Keep the source until two verified copies exist. One working preview is not enough.
Sources and technical references
FAQ
Questions about this recovery case
Can write-protected memory card be recovered in this situation?+
A card that still reads but refuses every write has either been locked mechanically or has locked itself. The difference matters: a switch can be flipped back, while a controller that went read-only after detecting failing flash is telling you the card is at the end of its life. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not chase the registry keys, terminal commands or manufacturer utilities that promise to clear write protection.
Does scanning write to my memory card?+
Your memory card is only read. Nothing is saved to it.
How do I know whether the result is complete?+
Compare the file count and total size on the destination with what the card shows, and open a sample from the beginning, the middle and the end of the copy.