Windows
OS: Windows XP SP3 Processor: 2.4 GHz Dual Core Processor Memory: 2 GB(XP)/ 2 GB(Vista) Hard Disk Space: 13 GB free Video Memory: 256 MB Video Card: NVIDIA GeForce 8500 /ATI Radeon HD 2600 Sound: DirectX 9.0c Compatible Other Requirements:Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include Steam Client, DirectX 9, Microsoft .NET 4 Framework, Visual C++ Redistributable 2005, Visual C++ Redistributable 2008, Visual C++ Redistributable 2010, and AMD CPU Drivers (XP Only/AMD Only)