I've had this problem for a while. I reluctently just used windows. I no longer wish to be without linux on my laptop. Why is this happening:
Either with CD or USB install the installer cannot get past bootup (it stops at the kubuntu splash). With nomodeset it sometimes manges to get to the run or install option, but freezes shortly after. I eventually managed to get it installed by adding noapic acpi=off and nomodeset together as a last ditch effort.
However with these options on its just, terrible. It doesn't show battery options, the keyboard, even on a light and fast keypress, occasionally spams keys as if I had been holding them down for several seconds. As well as not being able to install AMD drivers without adding --force. Which I just tried and now it starts without a GUI. Attempting to load the GUI with the startx command also fails.
My laptop is a Clevo P570WM with Intel i7-3970X CPU and 2x AMD Radeon HD 7970M GPU's. The Ubuntu distro is Kubuntu 14.04 x64.
Edit: Forgot to say I also tried to fix the problem by updating the kernel to 3.14.1-generic, didn't help.