ASUS ZenBook won't recognize external DVD-drive in BIOS

[WilliamBlake]

Hello everybody,

my ZenBook was getting repaired and they re-installed windows 8.1 (which was originally installed first, but then i installed win10). Now I want to restore a sytem image (with Win10) with the windows recovery disc, and my ZenBook doesn't have an internal DVD drive, so I bought an external USB-DVD-drive. The problem is, it won't show up in the boot section of the BIOS. There is only one available option, "Windows Boot Manager". When I try to add a new option, it only shows my internal hard drive filesystem. "Launch EFI Shell from filesystem device" just prints out "Not Found"

I already disabled fast boot, enabled CSM and updated the BIOS to its latest version.
I really don't now what else i could do now.

 

[Snipergod87]

I have seen cases where i need to unplug the device and plug it in on startup on new laptops for the BIOS to see it.

 

[WilliamBlake]

Okay, I tried 3 different cables now, still the same, I also tried all ports. The DVD drive lights upt on startup and i can clearly hear it spinning. Unplugging and Replugging also doesn't change anything.
How do i clear the CMOS?

And i recognized something else; when i start the "easy flash" utility in the BIOS, it shows the DVD in the filesystem, if it helps anyone

 

[WilliamBlake]

Could be the drive, but it does get recognized by windows, and also by my other PC, so i don't think the problem is there. I just tried a USB flash drive, and it also doesn't get recognized

 

[WilliamBlake]

I already updated my BIOS to the newest version available on the ASUS website

 

[WilliamBlake]

Okay I fixed it.
I enabled "Legacy USB Support" and "XHCI-Pre-Boot Mode" and now it shows the DVD drive and also the USB flash drive. Thanks everyone!