I'm trying to rebuild my Dell Dimension 2100 Desktop. I'm very computer illiterate. I want a desktop in addition to my laptop for when I go to college. I'd like for it to be pretty fast, have lots of memory, and be about as good or better as a new computer today. Also I'd like for it to have a DVD burner. I do have a budget of at or around $400.00 to work with. Please help me in my selection, and tell me what things I need to purchase and if possible where to purchase them from.