How to Fully Erase an SD Card. If you use your device's SD card to store images, audio files, documents and even email messages, your SD card might contains files that are hidden.

The best way to clear an SD card is to format it, which is like hitting a factory reset button; it'll erase every file, leaving just an empty card.

The Computer interface opens, listing the SD card as a removable drive. Right-click on the SD card entry in the Computer interface and choose "Format" in the context menu.

The best way to clear an SD card is to format it, which is like hitting a factory reset button; it'll erase every file, leaving just an empty card.