I had something similar, my DVD External Drive comes up in the BIOS as two things-one is UEFI and one is not (as in a prefix). Trying to boot up the UEFI one didn't work, but the non-UEFI one did.
Or wait, is this to carry on the installation? In which case disconnect the DVD drive-or set it to a low boot priority, with Windows boot manager and the HDD above it- and let Windows boot up the Hard Disk, and carry on the install.