My task today is to open up and copy some files to 700 brand new micro SD cards.

As I get going on this task I am finding that some of the Micro SD cards are telling me "sorry this drive is write protected"

To copy the files I am using a standard SD to micro SD card adapter, and a USB SD card reader / writer.

I have ensured that the switch is set to OFF on all of my adapters. As soon as I get a Micro SD that tells me it is write protected I can use the same adapter with another micro SD and it works fine, so I know the problem is not with my adapters.

My question is: How can I disable the write protection on a Micro SD card? This eHow article seems to indicate that there is also a physical switch on Micro SD cards. However I have personally never seen a Micro SD with a physical switch, and none of the ones I am using today have said switch.

Since these cards are brand new and thus empty are the ones that are telling me they are write protected simply useless? Could this be caused by some sort of defect in the cards?

3 Answers 3


Dust out your adapter. The sensor inside of it may be dirty and not recognizing the position of the switch.

I would also try another SD<->MicroSD adapter.

If you still experience problems, try putting a questionable SD card inside of a phone. I'd say if you get 2 or 3 cards that work fine in a phone, you should replace your USB card reader, see if maybe there is an issue with your USB connection, or use Linux to perform the task if possible which tends to behave a lot better regarding removal/insertion of USB devices, disks, and volumes than Windows (OSX also likely behaves a lot better).

If you find that the MicroSD cards are actually write protected (which should not be possible - the host/card reader is responsible for implementing the write protection and switch sensing, not the microcontroller in the card), I'd keep the bad ones and demand a refund.

  • Thank you. The USB SD adapter seems to have been bad. Strange thing is it would work sometimes.
    – FoamyGuy
    Mar 30, 2012 at 17:58

I have been fighting this issue for weeks and here is the way I found to fix. When MicroSD shows that it is write protected or locked. You have ensured if you are using an adapter the lock switch is in the correct position.

Download SD Formatter v4.0 from SD association website. Under Format Option Click to Format Type Full (Overwrite) Start this process. Please note you will lose all information on the card at this time.

After for me I still had to format the SD card in windows for it to recognize. Please allow a full format in windows and you should be good to go. I have not found anything else or any other website to be of any use when it comes to the microSD acting in this way.

SanDisk did issue me an RMA to return the unit. so if this does not fix the problem I would recommend contacting the MFR for a replacement.

  • This doesn't work for me. SD Formatter gives the error "The Memory Card is write-protected. Please release the write protect switch." No matter how I put the switch.
    – fivef
    Jun 13, 2020 at 10:58

When you have tried the write protection switch in both positions and in a second device, your card is probably broken. The card is in locked mode, which is a safety measure built into the card to avoid losing any data when something goes wrong. Locked mode is permanent. There is afaik no way to unlock it.

Don't throw your card away! Use the surprisingly long warranty by the card manufacturer!

Sandisk: 5 years - lifetime (detailed information depending on card)

Samsung: 5-10 years (detailed information depending on card)

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