Fix unreadable SD cards and flash drives

When you use an SD card or flash drive to install an operating system onto a PC or, more commonly, a single board computer such as the Raspberry Pi, you can be left with a disc that you can’t read in your PC. If you try to format it to turn it back into a standard removable drive it just won’t work.

The Dos commandline application, diskpart, is a low-level disk utility they can usually recover your drive and reformat it to usable device. But sometimes not even diskpart can read the data on the card or clean it correctly.

In this situation I find that the best method is to use one of the SD card burning packages to simply write a new operating system installation disc over the top of the drive’s content. It doesn’t really matter what burning packages use or what operating system image you burn, as long as you know it’s one that ends up with an installation drive that you can then recover using diskpart.

My preferred application is the Raspberry Pi imager which will download and burn an operating system onto your SD card with single click. If you look through the installation options you’ll find The Risk OS section which is ideal as it is only a 0.1 GB download which diskpart can easily revert back to standard SD drive.

The Procedure

So the basic procedure is to use your imaging software to burn an operating system onto your nonworking SD card flash drive.

Then open a command prompt on your PC with administrator privileges. Then type the command

diskpart

to start the disk partitioning app.

The list disk command will list your  available drives.

list disk

Use the select disk X command to focus on the drive you want to recover.

select disk 3

You can then use the list command again and you should see an asterisk beside your drive indicating that it is not in focus.

You can now clean the disc using the clean command.

clean

Next we need to create a primary partition

create partition primary

An format that to file system of your choice

format fs=fat32 quick

You should now have a working SD card or flash drive that you can use as normal in your PC.