Yeah, i got me a system like that and the same thing happened... The problem is the dual core processor. When sim city 4 was released they were merely a dream in a crazy hobo's mind. What you need to do is start your task manager (ctrl-shift-escape is the easiest way to do this), then start sim city, then press alt-tab to get back to the desktop, go to the task manager, and right click on simcity4.exe, then set processor affinity to either 0 or 1 - not both. Unforutenately, you have to do this pretty much every time as far as I know... still it is not too much of a hassle. Hope this helps!