thanks for the reply.
What I am talking about is before the linux booting process I think.
I know about the USB legacy mode setting, what I can say is that it did not help on my "PC / windows" computer and that I did not find such things on the EFI bios of the MAC I was on yesterday.
Again the question about whether or not boot from UBCD seems useless per see and prevent from booting in such situations.
Even if it did exist a workaround, something I think does not exists on some computers (like the aforementioned Mac or many PC) it would prevent many users from using UBCD. When you use UBCD you are often in trouble and this is not the kind of problem you want on top of the ones you already have
Yesterday I was confronted to a viral infection and there was no way out since both windows and UBCD did not recognize the keyboard. UBCD at "bios" boot time, and stupid windows at "F8" time.
I feel compelled to mention that most business PC (dell and the like) do not have a rich bios, with settings like legacy mode.
All in all, getting rid of this question greatly increase the chances than the next boot stage will load the necessary driver and allow UBCD use
Removing the "press Enter" line, won't help, because you need the keyboard afterwards to select an item in the menu.
If you are right and no usb drivers is loaded before that next menu, then there is no solution, and UBCD (and many other tools) will never be usable with those computers.
If that next menu comes after isolinux/syslinux loading then updating it may help solve the problem.
Or do you mean that the first question is already under isolinux/syslinux control (and thus updating could help) ?