The G-Wizard products run on Windows and Machintosh systems as Adobe AIR applications. As such, the Adobe AIR System Requirements are applicable. G-Wizard Calculator is very lightweight, and it doesn't take much of a machine to run it. G-Wizard Editor includes a lot of graphics to support the Toolpath Simulation, so more powerful systems will run faster.
Your machine will need an Internet connection to install G-Wizard, and then it needs to connect once every 4 weeks. In between the 4 week check-in intervals, no Internet connection is needed.
For G-Wizard Editor, you can check whether your graphics card is supported by checking whether the graphic at the bottom of this page is animated.