I have recently bought a laptop with windows 8 (EFI) installed. I thought I'd be able to handle installing 12.04.2 relatively easily - how wrong could I be?

Using a live-usb I made using startup disk creator on ubuntu with a 64 bit .iso file...

*I First tried to install ubuntu in legacy mode without a boot partition which needless to say didn't work.

*I then reinstalled ubuntu with the boot partition, still using legacy. This time I managed to get the grub menu to show up but I only had the choice of booting into Ubuntu. (unless I told it to boot in EFI mode and then it only booted windows)

*I tried boot-repair both times and that didn't help things at all.

I now realise I can't boot ubuntu in legacy mode if windows is booting in EFI.

So I need to boot from the live-usb in EFI mode. But when I enable EFI mode and boot from USB FLASH DRIVE it says: FLASH DRIVE HAS BEEN BLOCKED BY THE CURRENT SECURITY POLICY. (or something to that effect)

Is there a problem with the way I made the live-usb?

How am I supposed to boot from the live-usb in EFI mode if I get the error message each time?

I realise lots of people are asking these sorts of questions at the moment, but I've been looking for a while and I haven't found any solutions that work. :/ Thanks for your help!