Stop! Wait! I know what you’re thinking. This SD card has more the 50MB on it, but Windows won’t format it properly. Even Disk Management is failing.
For anyone who backs up their Raspberry Pi images or re-images their SD cards, this can be a huge hassle. Let alone if that unfortunate moment has come and your SD card or USB stick is showing no memory available at all. The formatting is just ruined. Breathe deep there are utilities out there to help.
The most important will be SD Card Formatter from the SD Association.
This will heal that busted memory, repave the rough topography on that card and bring it back to life. One click, it runs, you’re done. Off to write another image to your Raspberry Pi.
The second tool which is super pervasive and most likely the reason you’re in this position to begin with is Win32 Disk Imager.
This is the king of reading and writing SD and USB cards. But be cafeful when he bites you’ll need to go back to SD Card Formatter (what an intuitive name) to make it better.
Take this as a sign you should backup all your SD Cards, so that you can mix and match your fine tuned operating systems between multiple devices. You can even use it as a very heavy handed form of version control, but sometimes when working on small embedded systems it’s just the most practical way to work.