Run cmd.exe
as an administrator then run diskpart
with the following commands:
Shows all mounted disks. Find your USB flash
list disk
Selects the disk that future commands will use. Replace n with the disk # for your USB flash drive. NOTE: Be careful that you don’t select your hard disk! The next command will wipe the selected drive clean.
select disk n
Erases all previous partition & volume information on the flash drive.
clean
Partitions the flash drive as one partition for the whole drive.
create partition primary
Selects the new partition so future commands will operate on it.
select partition 1
Marks the new partition as active so the BIOS/UEFI can boot to it.
active
Formats the partition as FAT32. (NOT NTFS!) EXTREMELY IMPORTANT!
format fs=FAT32 quick
Assigns a drive letter to the flash drive.
assign
Exits diskpart
exit
At this point your USB drive is formatted. DO NOT format the drive with Windows Explorer, you will not be able to boot from it.