Booting a different OS from a Windows8 Computer
As you may be aware new computers that ship with Windows8 have this thing called Unified Extensible Firmware Interface along with something else called secure boot. Now what it supposedly does is makes your computer more secure and I'm sure it has its advantages. The disadvantages are that it doesn't let you boot into anything other than Windows8. Surely Microsoft didn't do this on purpose to dissuade people from trying non-Microsoft operating systems...
Fortunately it is pretty easy to disable, you'll have your favorite distro on in no time. First we need to go into the BIOS, since the function key to do this varies for different brands I'd recommend start pressing the escape key when you boot up and it will give you a help screen of sorts telling you what function keys do what.
Now you are in BIOS, you'll have to navigate to find the Boot Options. For me this was on the main screen, I selected it, pressed enter and I was presented with the sub options you see here. They may be displayed differently but all the options are going to be the same.
Look for Secure Boot and Legacy Support, disable Secure Boot and enable Legacy Support.
Uh Oh! Scary message saying our computer might not work if we do this. Well you should ALWAYS keep your data backed up anyway, but I didn't run into problems, just select "Yes".
Congratulations you can now install a better operating system. I'll leave that step up to you, but if you are looking for recommendations, grab and Ubuntu CD they make the install process and dual boot process about as easy as it gets.