Not to be a smart alek but doesn't the evidence seem to indicate that there's something with your system? You have a RAdeon, you have WIndows XP right? But it won't install?
You have the Radeon IGP. If ATIs own drivers won't install on your computer, and loading up a fairly unintensive strategy game causes your computer to go black and reboot, doesn't that indicate that something odd is happening?
The issue is your video driver. I can almost garuantee it. If you can just get your graphics driver up to the latest version I suspect many problems will go away.