14.04 - Forcing Ubuntu to boot in EFI mode

I have a Gigabyte motherboard with an "Hybrid-EFI" Award Bios. In the Bios, there's an option to boot from the DVD Drive in EFI mode, but no such option exists for for USB booting. I was able to install Windows 10 in EFI mode through the DVD drive, but I'm unable to do the same with an Ubuntu 14.04 64-bit DVD. Is there a way a FORCE Ubuntu to boot in EFI mode, whether from a USB or DVD?

My exact motherboard model is Gigabyte GA-78LMT-USB3 rev 5.0

I looked on another Ask Ubuntu for making a EFI Ubuntu installer, but was unsuccessful for me.

I owned such a computer once. The Gigabyte Hybrid EFI is, hands down, the single worst x86/x86-64 EFI implementation I've ever encountered. (Note that I currently own 12 EFI-based computers, and I've used countless more at work.) See this page of mine for details of my experiences with this system.

Overall, my recommendation is to abandon your attempt to use EFI mode on that computer. Re-install Windows in BIOS mode and install Ubuntu in a BIOS-mode dual-boot. That will almost certainly go much more smoothly and be much less likely to cause problems in the future.

If you must use EFI mode for some reason (like if you've got an over-2TiB hard disk), then you should first be aware that the computer doesn't remember its boot options, so you must use a fallback filename on the EFI System Partition (ESP). You can install in either BIOS mode or EFI mode and then install an EFI-mode boot loader using the fallback filename of EFI/BOOT/bootx64.efi -- that is, you must copy EFI/ubuntu/ to EFI/BOOT and rename shimx64.efi or grubx64.efi to bootx64.efi in EFI/BOOT. (Alternatively, you can do something equivalent with another boot loader, like ELILO or rEFInd.) See this section of one of my pages for a little more on this approach. Note that if you install in BIOS mode, you'll need to install the boot loader after doing the main installation, and this can be awkward if you're in BIOS mode.

One major caveat is that, if you're dual-booting with Windows, the Gigabyte EFI might favor the Windows boot loader (EFI/Microsoft/Boot/bootmgfw.efi) over the fallback filename of EFI/BOOT/bootx64.efi. If so, you'll need to give your boot manager the Windows boot loader name and configure it to boot the Windows boot loader under another name. Boot Repair can do this in a semi-automated way for GRUB by using an option on the Advanced menu; or the mvrefind command can help out if you use my rEFInd.

The above hoop-jumping is one of the reasons I recommend you abandon an EFI-mode installation on anything using a Gigabyte Hybrid EFI.