use virtual PC and install the different software on different platforms. I worked for Autodesk doing screen shots for their user manuals in 15 languages on 10 different operating systems this is the easiest way to do it without having to own 20 PC,s.. plus if your machine is up to it you can run them all at once :)
is not as messy as multiple accounts login logout all day, but that method would be cheaper.
My 2 cents
Cheers