I had 2GB ram and it was working fine, upgraded to 3GB and plays slow especially in career mode, spec: intel core 2 cpu 6400 2.13ghz, 32 bit windows 7 professional.You should tell us more abut the hardware of your PC. Components like the CPU, VGA, RAM, PSU and which operating system you are using. Without that information is really hard to help you and tell you where it might be the problem.