Cards may be formatted in the FAT32 file system by the following methods:• Astell&Kern player - Settings > System Information > Erase SD Card• Windows OS Computers – Start Menu > Devices and Drives > Select desired SD card with right mouse button > Click Format > FAT32 > Ok• Mac OS - In Disk Utility, which can be found in Applications > Utilities > Disk Utility.  Choose format as MS-DOS (FAT)• [Please Note] When formatting cards, all data stored on the card will be erased.