Hello
Had an interesting one here. I dowloaded the final version 14 ISO. And then use imagewriter to make a bootable USB.
I thern put it in the laptop i had trouble with. It cae up with this error below at bootup. I also tried it on my main laptop an got same issue:
SYSLINUX 4.07 EDD 2013-07-25 Copyright © 1994-2013 H. Peter Anvin at al
NO default or UI configuration directive found !
boot:
regards
Mark