Realflight G5 runs on my Windows 7 laptop with 2 gig ram and a slow 1.6 ghz cpu(with min graphics). I just don't like it when the hackers an virus developers know more about my OS then I do. Now I have to teach myself again to keep them out. I found that with 7 I have less control over my computer then ever. I am sure that will change as I spend more time using it. It is just a pain and yes I admit- change is also.BW