Because there will be some system files when the U disk is formatted as FAT32 disk format, there is still room for use.

1 and USB flash drive /SD card still occupy space after formatting, as shown in the figure.

2. We download a Chinese cabbage online and open the software, as shown in the figure.

3. As shown in the figure, select Return Space.

4. At this time, you will be prompted to clear the data, so back up the data on the U disk /SD card before.

5. Prompt that the USB flash drive is initializing. Wait a minute, it will be fine.

6. After processing, we will reformat the U disk /SD card under Windows system.

7. The occupied space is gone, and the USB flash drive is formatted successfully.