Trouble with The Sims 2?

I've never had any issues before but now I open the Sims game and the opening video plays fine, and then it reaches the initial opening screen & freezes before it loads anything at all. I can't even get to the neighborhood selection menu. It also won't allow me to minimize the game, so I have to use ctrl-alt-delete to open the task manager - which then says the game is 'not responding' and therefore I have to close it. I miss my game and was wondering if anyone knew how I could solve this?