MINIMUM: OS:Windows Vista Processor:2 GHz Dual Core Memory:2 GB RAM Graphics:NVIDIA GeForce 8600 GT / ATI Radeon HD 2600 XT or greater DirectX®:9.0 Hard Drive:20 GB HD space Sound:DirectX Compatible Other Requirements:Broadband Internet connection Additional:Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include Steam Client, Visual C++ 2008 Redistributable, DirectX and Microsoft .NET 4. RECOMMENDED: OS:Windows 7 Processor:2 GHz Dual Core (Intel Core 2 Duo 2.4 GHz or Athlon X2 2.7 GHz) Memory:4 GB RAM Graphics:NVIDIA GeForce 9000 series / ATI Radeon HD 3000 series or greater DirectX®:9.0 Hard Drive:20 GB HD space Sound:DirectX Compatible Other Requirements:Broadband Internet connection Additional:Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include Steam Client, Visual C++ 2008 Redistributable, DirectX and Microsoft .NET 4.