Q:

Cannot boot Ubuntu 12.04 (no boot option)

This might be a common issue, but I cannot find any other words to describe my problem. After I uninstalled openSUSE and deleted the boot option towards this OS in order to have no trouble booting on Windows 8, I cannot boot ANY linux distro anymore after they're being installed. The reason why I post this on ASK UBUNTU is that Ubuntu is my favorite distribution and I an currently using it in a live device. I do not like Windows 8 that much (I got my ASUS laptop XC551CA less than two months ago).
I know what to do in order to get to the Ubuntu desktop on a live device. My problem is that I cannot find ANY boot option in the BIOS UEFI. I do not know how to add a boot option in the BIOS. I have tried Linux mint and openSUSE once more and both do not work.
I really need to get with Ubnutu as soon as possible. I need to keep video editing on kdenlive, I started several months ago and I can't do on a virtual machine on Windows (no! It doesn't work either and it is a painful experience!)
Anyone who experienced my problem and solved it, or anyone familliar with this issue is more than welcome to answer and/or comment!
As usual, I appreciate your time and wisdom. This is very urgent and I am pretty much un the rush.
Thank you!
Laptop identification:
ASUS X551CA X series
750 GB hard disk
Windows 8 alongside Ubuntu 12.04 LTS
Have tried several distros (and a windows program EasyBSD: unsuccessful!)
Experienced with installing and uninstalling linux distributions
Completely not experience with creating the boot options
Not really familliar with the BIOS
Boot repair ? Didn't work (both the CD and the program on the live USB that I downloaded once I booted onto Ubuntu)
Thank you again!

A:

I've had a similar issue before where after installing Ubuntu 12.04 alongside Windows 7, it would never allow me to boot into Ubuntu. To solve the issue I utilized Boot Repair from a Ubuntu Live USB. There's an explanation of the tool located here: 

