How to make Windows 7 ISO to USB
[message_box title=”USB size” color=”red”]The USB key needs to be at least 4 GB in size.[/message_box]
Before installing Windows 7 from the USB key, you will need to enable Legacy USB storage detect in the BIOS.
You can only create a 64-bit Windows 7 bootable USB flash drive if your current Windows 7 installation is also 64-bit.
CMD as admin
diskpart
list disk
select disk №
clean
create partition primary
select partition 1
active
format fs=ntfs label="Windows 7" quick
assign
exit
Mount ISO with daemontools. Copy everything from ISO to newly created partition on USB stick.
Ready to boot from.
[message_box title=”UEFI/BIOS” color=”red”]If you have UEFI instead of BIOS motherboard, then you will need to temporarily disable Secure Boot to use the USB to install Windows. After installation is complete, you can enable Secure Boot again.[/message_box]
Source: Windows Seven Forums.