Unable to boot from cd or live usb on Toshiba satellite U945-S4140

I am trying to completely switch over to ubuntu from a my toshiba ultrabook. Link to product page: http://www.toshiba.com/us/computers/laptops/satellite/U940/U945-S4110
I previously had linux mint dual booted with windows 8, and to get that to work my friend had to do something to the computer. I have the iso for ubuntu 14.04 LTE loaded onto a cd, and I have tried starting my computer with my external usb disk drive, but I keep getting the message "Reboot and Select proper Boot device or Insert Boot Media in selected boot device and press a key" even though I have the UEFI set up to boot from my cd drive. I was able to previously install ubuntu, but right at the end of the install the bootloader failed to install correctly. How should I proceed to be able to join the ubuntu family?