Insert the SD card into your computer
Open File Explorer on Windows or Disk Utility on Mac
Back up any important files from the SD card
On Windows, right-click the SD card drive and select Format
Choose FAT32 as the file system
Set the allocation unit size if needed
Uncheck Quick Format only if you want a full format
Click Start and confirm the warning
On Mac, open Disk Utility
Select the SD card in the sidebar
Click Erase
Choose MS-DOS (FAT) or FAT32 if available
Select Master Boot Record if required
Click Erase to format the card
Eject the SD card safely after formatting