Theres OS which has the spinning box thingymabob installed ready... (I forgot the name again, I need to work on my memory)
and all your games cant work on it, you dont have directX, and I never myshelf tried how GameGuard works with my Ubuntu... I have feeling that theres no way it will work.
Why Linuxes and Mac:s dont get viruses, most people use Windows so for those who make them (them=viruses) its better to make virus for windows than Mac.
