First, I recommend you enter your firmware setup utility (usually done by pressing Del or a function key just after powering on the computer) and disabling Secure Boot. Unfortunately, the details of how to do this vary from one computer to another, so I can't be very precise about how to do it.
If that doesn't work, then you might try downloading the USB flash drive version of my rEFInd boot manager and booting from that while the Ubuntu CD is in the drive. With any luck, rEFInd will detect the Ubuntu CD and give you a boot option for it, and that will work. If you don't see the Ubuntu CD immediately, try hitting the Esc key.
If that doesn't work, try creating a bootable USB flash drive from the Ubuntu CD. It's possible that your computer will like that better than a CD.
One more point: The option to install Ubuntu within Windows (that is, using WUBI) is unsupported on EFI-based computers, which yours is. Don't try to get that working, since it's a waste of time.