Insert the micro SD card into your computer using a card reader
Back up any important files on the card
Open File Explorer on Windows or Disk Utility on Mac
Select the micro SD card
Choose the format or erase option
Set the file system to FAT32
Set the allocation unit size to default if available
Enter a volume label if desired
Start the format process
Confirm any warnings or prompts
Wait for the formatting to complete
Safely eject the micro SD card