Format the Drive

The steps here are to use the command line to format the disk properly using the diskpart utility. 

    
Plug in your USB Flash Drive
    
Open a command prompt as administrator (Right click on Start > All Programs > Accessories > Command Prompt 
and select ：Run as administrator；
    
Find the drive number of your USB Drive by typing the following into the Command Prompt window:
    
diskpart
list disk
    
The number of your USB drive will listed. You・ll need this for the next step.  
I・ll assume that the USB flash drive is disk 1.

Format the drive by typing the next instructions into the same window. Replace the number ：1； with 
the number of your disk below.
    
select disk 1
clean
create partition primary
select partition 1
active
format fs=fat32 / fs=ntfs
assign
exit
    
When that is done you・ll have a formatted USB flash drive ready to be made bootable.