Installing Windows on a Partitioned Second Disk Drive?

I recently started a 3D parametric modeling course using Autodesk Inventor. I want to be able to use the free student software that is available for download from the Autodesk site but need to get my mac up to spec before I can. I have a Mac Pro 1.1 Quad Core 2x2.66 GHz. My first problem is that my Hard Disk is pretty full and to run Inventor I will of course have to install windows on a partition. To deal with this issue I want to install a second Hard Disk and partition it so that I have windows installed there with the Autodesk Inventor software. Can anyone tell me if this will work? Can I leave my original Hard Disk alone, install a second and partition it to run Windows from there? Also, if you could give any feedback to me in layman's terms that would be helpful as I am not a techie.