You can use Rufus or Windows Diskpart for this purpose. I recommend Rufus, because it is easier.
Download Rufus from here
Plug in your USB stick and Rufus will set all the options for you. You don't have to change anything.
You only need to browse the path to your Windows ISO image and click Start
OPTION2 - DISK PART
Run command prompt with administrative previledges
Start > type cmd > Right-click cmd > Run as Administrator
diskpart list disk select disk 1 (my USB disk is listed as 1, that's why typed 1) clean create partition primary select partition 1 active format fs=ntfs quick
Now mount the Windows ISO and copy the boot sector from ISO (F) to USB Flash Stick (E)
C:\Windows\system32>F: F:\>cd boot F:\boot>bootsect /nt60 E: F:\boot>exit