If you're new to UEFI, you're in for a real education. I've been struggling with getting the nuances of it through my skull the last couple of years and I'll just say it's very new and different from anything you've seen with earlier versions of Windows. If you want a link for some info, you could start with Wikipedia here: http://en.wikipedia.org/wiki/Uefi . The purpose for this change is better security, but a lot of us think it's too much of a good thing!
I have Windows 8.1 installed on two desktops at home and 4 that I support where I do volunteer work. I hasten to add that I started with Windows 8.0 pro on systems already running Windows 7. Then I created a new partition for Windows 8 and the install went smoothly - I didn't get anything like the error you mention, but maybe if you start out with an 8.1 disc, that's changed. Anyway I've been able to upgrade to 8.1 and all the subsequent updates without problems.
So if you have the hard drive space, try creating a new partition for Windows 8.1 and see if you can install it in that. That will give you a dual boot setup where each OS can see the other's partition. I'd sure be interested to know how you make out if you try it. Here's a link to what Microsoft says about it
http://support.microsoft.com/kb/2481490/en-us . It suggests you're using UEFI to boot instead of the legacy BIOS. If you can switch back to booting with BIOS (which is what I did), you may be able to get around the problem.
In the mean time I'll see if I can find out more about this message and how to deal with it.
Edited by wpgwpg, 07 July 2014 - 03:04 PM.