i am using windows 10 in toshiba satellite laptop and i dont want this window 10 and i want to install window 7 ultimate. But i try many techniques to install from cd, but i cant do it. i also did some settings in bios such as enable or disable, but its not work. in bios they just showing HDD and USB, but not CD-ROM, than how i install windows 7 ultimate. Its my brand new cd of windows 7 ultimate.