Create bootable USB flash drive using DISKPART

Prepare: PC running windows 7, USB flash drive 4GB, media windows DVD (or ISO file)
Step 1: Insert windows DVD into drive (or mount ISO file) and make note of the drive letter
Step 2: Insert USB flash drive into computer and make note of the drive letter
Step 3: Go to Start menu | type cmd | righ-click cmd.exe | select Run as Administrator
Step 4: Run diskpart to prepare...
diskpart
list disk
select disk ?
clean
create partition primary
select partition 1
format fs=ntfs quick label="Win8.1-Pro-x64"
active
exit
* You should still be in the command prompt window
Step 5: in the command prompt windows type drive letter of media windows
C:\Windows\system32>H:
H:\cd boot
H:\boot> bootsect.exe /nt60 I:
H:\boot>exit
Step 6: copy all files and folders from media windows to usb flash drive (in my case: copy from H: to I:)