dadyrghluv is absolutely correct here. When I first got the game I had 512MB ram but only the integrated graphics card and it would freeze when loading as you described. So I got a gforce fx5200 128MB graphics card (MSI) and it is has worked fine since. It only cost like $80 for the card and that was almost 2 years ago so you should be able to get one cheap. ram is cheap too.
Don't go back to sc3000. You will be missing out.