I cannot vouch for the hardware your purchasing as to it working in a Virtual Machine although I'd expect that it would however a default Fusion 2.x Easy Install Windows XP virtual Machine meets and or exceeds all of the requirements however you can verify via the target Virtual Machines Settings in Fusion what you have allocated for RAM, Hard Drive size, USB 2 etc. If you have 3D enabled the video memory is 128 MB. As far as the Processor it uses the physical processor of the Host and the Processor on a Mac capable of running Fusion is so much more advanced then a PIII 1Ghz it not even a spec you need to verify.