Run Command Prompt as Administrator.
Type list disk command so that diskpart lists all disks connected to your computer.
Be very careful here! # is the disk number of your USB drive, You should replace # with the correct disk number
select disk #
!!! Make sure you selected the correct disk.
Create a new partition on the USB drive after DiskPart succeeded in cleaning the disk.
create partition primary
The following command formats the newly created partition to FAT32 file system.
format fs=fat32 quick