Hi, So I have Asus Zenbook UX302LG. I am using USB 2.0 LG GP50 portable dvd-drive. I downloaded the MSDN windows 8.1 update x64 iso and burnt it at 6x speed through imgburn. Problem is, when I get to the windows 8 installation screen, it gives me "missing dvd-drive from usb/media" etc. I tried Windows 7 sp1 x64 same issue. I don't know how to resolve it. Please help! my Asus laptop has usb 3.0 ports only.