Mac Mini 2010: DualBoot (BootCamp) OSX Mavericks + Windows 8.1
I tried to use virtualbox by enabling it permissions access to my whole drive. This also did not work. 

The only available solution, after extensively scanning the web, is to install with the native dvd drive.

However, I am surprised that the community has not defined a better solution. One where one can dual boot windows/ or, bootcamp windows in a macbook 2010 (for example) where the optical drive has been replaced by a second hard drive [without removing the second drive and reinstalling the optical drive]. I am also not satisfied with the cloning a drive option as this too requires removing drives and reinstalling and gaining access to a second mac. 

I think that ubuntu (http://www.askubuntu.com/) may be able to define a solution using unix code to fix the problem once and for all!