OS: Windows Vista Service Pack 2 / 7Service Pack 1 / 8 / 8.1* (*NVIDIA video card recommended if running Vista OS) Processor: Intel Core 2 Quad CPU Q6600 @ 2.40GHz (4 CPUs) / AMD Phenom 9850 Quad-Core Processor (4 CPUs) @ 2.5GHz RAM: 4 GB Hard Drive: 65 GB free Video Card: NVIDIA 9800 GT 1GB / AMD HD 4870 1GB (DX 10, 10.1, 11) Sound Card: 100% DirectX 10 compatible DirectX: 10 Keyboard and Mouse