Step1. When the command prompt opens, enter the following command:

DISKPART and thi enter. 

LIST DISK and hit enter

Once you enter the LIST DISK command, it will show the disk number of your USB Flash Drive.  In this step you need to enter all the below commands one by one and hit enter. 

SELECT DISK 1(Replace DISK 1 with your disk number)

CLEAN

CREATE PARTITION PRIMARY

SELECT PARTITION 1

ACTIVE

FORMAT FS=FAT32 QUICK    (Format process may take few seconds)

ASSIGN

EXIT

이후 FAT32로 64GB메모리 포맷이 필요할 경우 GUIFORMAT 프로그램을 이용해서 포맷 가능함.