I recently got an acer aspire ES15 second hand, and it came pre installed with windows 10 and it's very slow so I bought windows 7 and it just wont work. I used the disc to usb tool from microsoft to install it on a usb because the dvd/cd drive doesnt work on the laptop. So i turn off the secure boot from the bios otherwise it doesnt work. The little windows logo lights freeze half way and i guess the whole laptop freezes because i left it for 2 hours and it hasnt unfreezed. It happens every time. I tried legacy boot mode and i get to the installation but it says straight away that "a required cd/dvd drive device driver is missing" I tried everything i found on the internet for that and it nothing worked. I also used wintoflash and rufus severalal times just in case something went wrong but its still the same. Can anyone help? Any help is appreciated.