OK, so i just got the Sims 3 for the pc. I have an old computer (i thinks its 2005) w/ windows xp. I put the game in and after it took forever to load i got in to the regular game and it ran so slow that is want fun. Even though the game requires 5,600mb i checked my computer and i have more than enough space left. I was considering getting an external hard drive? Is it just because its an old operating system? I have 1 day left to return it. What should i do?

Yeah, i have enough RAM, but im thinking the external hard drive will help w/ that. YEah, i defrag like every day.